diff --git a/.gitignore b/.gitignore
index 98bc672..a70882d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -75,6 +75,8 @@ social_posts/
 
 # Generated analytics artifacts (rebuilt from cost_tracker)
 data/costs.db
+data/costs.db-shm
+data/costs.db-wal
 data/cost_reports/
 
 # Generated caller avatars
diff --git a/backend/main.py b/backend/main.py
index 19a715f..8fca9bb 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -540,6 +540,15 @@ def detect_host_mood(messages: list[dict], wrapping_up: bool = False) -> str:
 
 
 
+class EmptyCallerBackgroundError(RuntimeError):
+    """Raised when a caller prompt is built from a background with no identity.
+
+    A hollow prompt still generates dialog — the model invents the most generic
+    late-night radio call it can (relationship trouble, every time) and a regular
+    like Silas loses all his lore. That failure is silent and costs a whole show,
+    so refuse to build the prompt instead."""
+
+
 def get_caller_prompt(caller: dict, theme: str = "") -> str:
     """Caller system prompt. Identity carries the weight."""
     name = caller.get("name", "")
@@ -547,6 +556,12 @@ def get_caller_prompt(caller: dict, theme: str = "") -> str:
     situation = caller.get("situation", "")
     reason = caller.get("reason_calling", "")
     want = caller.get("secret_want", "")
+    if not (name or identity or situation):
+        raise EmptyCallerBackgroundError(
+            "Refusing to build a caller prompt with no name, identity, or situation — "
+            "session.caller_backgrounds was never populated. Call populate_backgrounds() "
+            "(POST /api/session/reset) before taking calls."
+        )
     opening = caller.get("opening_line", "")
     details = caller.get("specific_details", []) or []
     detail_str = " | ".join(f"- {d}" for d in details)
@@ -952,17 +967,14 @@ class Session:
                     return i
             return 999  # never appeared
 
-        regulars_for_tonight: list[dict] = []
-        for r in active_regulars:
-            misses = _shows_since_last(r.name)
-            prob = min(1.0, 0.4 + 0.3 * misses)
-            if random.random() < prob:
-                regulars_for_tonight.append(
-                    {"name": r.name, "voice": r.voice, "age": r.age,
-                     "lore": r.lore_body, "arc_state": r.arc_state,
-                     "_misses": misses, "_prob": prob}
-                )
-        regulars_for_tonight = regulars_for_tonight[:3]
+        selected = _select_regulars_for_tonight(active_regulars, _shows_since_last)
+        regulars_for_tonight: list[dict] = [
+            {"name": r.name, "voice": r.voice, "age": r.age,
+             "lore": r.lore_body, "arc_state": r.arc_state,
+             "register": r.register, "explicitness": r.explicitness,
+             "_misses": misses, "_prob": prob}
+            for r, misses, prob in selected
+        ]
         if regulars_for_tonight:
             names = ", ".join(f"{r['name']}(miss={r['_misses']},p={r['_prob']:.2f})"
                               for r in regulars_for_tonight)
@@ -1152,10 +1164,10 @@ class Session:
         self.start_prewarm()
 
     def _get_recent_summaries(self) -> list[str]:
-        """Return caller name+situation strings from the last 2 lineups, so Sonnet
-        can avoid repeating archetypes. Empty list on first run."""
+        """Return caller name+situation strings from the last LINEUP_DEDUP_SHOWS
+        lineups, so Sonnet can avoid repeating archetypes. Empty list on first run."""
         history = _load_lineup_history()
-        recent = history[-2:]
+        recent = history[-LINEUP_DEDUP_SHOWS:]
         summaries: list[str] = []
         for record in recent:
             for caller in record.get("lineup", []):
@@ -1257,7 +1269,77 @@ CHECKPOINT_LINEUP_MAX_AGE = 3600  # 1 hour
 
 # --- Lineup History (for anti-repeat context across sessions) ---
 LINEUP_HISTORY_FILE = Path(__file__).parent.parent / "data" / "caller_lineups.json"
-LINEUP_HISTORY_MAX = 10
+LINEUP_HISTORY_MAX = 20
+# How many past lineups to show the batch generator as "don't repeat these".
+# Replaces the cross-episode topic dedup deleted in Phase 5B (commit 83c7f44),
+# which left only a 2-show window and let archetypes recycle.
+LINEUP_DEDUP_SHOWS = 10
+
+MAX_REGULARS_PER_SHOW = 3
+GROUP_TWO_UP_CHANCE = 0.15  # Odds a faction gets two slots — "both sides tonight"
+
+
+def _weighted_sample(entries, k, rng):
+    """Sample k of [(regular, misses, prob)] without replacement, weighted by
+    group_weight. An anchor carrying an arc needs the group's slot more often
+    than a texture character does, or the arc takes 30 episodes to resolve."""
+    pool = list(entries)
+    picked = []
+    while pool and len(picked) < k:
+        weights = [max(float(getattr(e[0], "group_weight", 1.0) or 1.0), 0.0) for e in pool]
+        total = sum(weights)
+        if total <= 0:
+            picked.append(pool.pop(rng.randrange(len(pool))))
+            continue
+        target = rng.random() * total
+        upto = 0.0
+        for i, w in enumerate(weights):
+            upto += w
+            if target <= upto:
+                picked.append(pool.pop(i))
+                break
+        else:
+            picked.append(pool.pop())
+    return picked
+
+
+def _select_regulars_for_tonight(active_regulars, shows_since_last, rng=random):
+    """Pick tonight's regulars, collapsing factions so one group can't crowd out
+    everyone else. Returns [(regular, misses, prob)].
+
+    A group normally gets a single slot. On a GROUP_TWO_UP_CHANCE roll it gets
+    two, preferring the group lead plus one other member — the leader's version
+    of events and someone else's, in the same episode."""
+    candidates = []
+    for r in active_regulars:
+        misses = shows_since_last(r.name)
+        prob = min(1.0, 0.4 + 0.3 * misses)
+        if rng.random() < prob:
+            candidates.append((r, misses, prob))
+
+    grouped: dict[str, list] = {}
+    selected: list = []
+    for entry in candidates:
+        group = getattr(entry[0], "group", "")
+        if group:
+            grouped.setdefault(group, []).append(entry)
+        else:
+            selected.append(entry)
+
+    for members in grouped.values():
+        cap = 2 if rng.random() < GROUP_TWO_UP_CHANCE else 1
+        if len(members) <= cap:
+            selected.extend(members)
+            continue
+        leads = [m for m in members if getattr(m[0], "group_lead", False)]
+        rest = [m for m in members if not getattr(m[0], "group_lead", False)]
+        if cap >= 2 and leads and rest:
+            selected.extend([leads[0]] + _weighted_sample(rest, 1, rng))
+        else:
+            selected.extend(_weighted_sample(members, cap, rng))
+
+    rng.shuffle(selected)
+    return selected[:MAX_REGULARS_PER_SHOW]
 
 
 def _load_lineup_history() -> list[dict]:
@@ -2573,7 +2655,9 @@ async def get_callers():
     return {
         "callers": callers,
         "current": session.current_caller_key,
-        "session_id": session.id
+        "session_id": session.id,
+        "lineup_ready": bool(session.caller_backgrounds),
+        "lineup_count": len(session.caller_backgrounds),
     }
 
 
@@ -2630,6 +2714,13 @@ async def start_call(caller_key: str):
     if caller_key not in CALLER_BASES:
         raise HTTPException(404, "Caller not found")
 
+    # Backgrounds only land in the session via populate_backgrounds(), which used
+    # to be reachable only through POST /api/session/reset. Taking calls without
+    # hitting reset left caller_backgrounds empty for the whole show.
+    if not session.caller_backgrounds:
+        print("[Session] No caller lineup loaded — populating before first call")
+        await session.populate_backgrounds()
+
     # Guard against double-click or rapid switching
     if session.current_caller_key == caller_key:
         return {"status": "already_on_call", "caller_key": caller_key}
diff --git a/backend/services/audio.py b/backend/services/audio.py
index 683cd7b..edefb88 100644
--- a/backend/services/audio.py
+++ b/backend/services/audio.py
@@ -72,7 +72,7 @@ class AudioService:
         self.ident_channel: int = 15   # Channel for idents (stereo: ch 15+16)
         self.monitor_device: Optional[int] = 14  # Babyface Pro (headphone monitoring)
         self.monitor_channel: int = 1  # Channel for mic monitoring on monitor device
-        self.phone_filter: bool = False  # Phone filter on caller voices
+        self.phone_filter: bool = False  # Phone filter on caller voices — applied in post, not baked in
 
         # Ad playback state
         self._ad_stream: Optional[sd.OutputStream] = None
diff --git a/backend/services/caller_gen.py b/backend/services/caller_gen.py
index 6893e68..1e888f1 100644
--- a/backend/services/caller_gen.py
+++ b/backend/services/caller_gen.py
@@ -66,6 +66,14 @@ def resolve_voice(suggestion: str, roster: list[str]) -> str:
     return random.choice(roster)
 
 
+# Per-character dial rather than a global switch, so explicitness varies by who
+# called instead of the whole show moving together.
+_EXPLICITNESS_GUIDANCE = {
+    "low": "alludes to sex obliquely at most, deflects or changes the subject when it comes up — their discomfort is part of the characterization",
+    "medium": "references sex bluntly and matter-of-factly when it's relevant, but doesn't dwell or go into detail",
+    "high": "talks about sex and kink frankly, graphically, and without embarrassment — it is simply how this person talks",
+}
+
 BATCH_SYSTEM_PROMPT = """You are writing a roster of callers for Luke's late-night radio show, broadcast out of Alpine, Texas, in the Big Bend country of far West Texas.
 
 WHERE THESE CALLERS LIVE: The show's world is the Big Bend region of far West Texas — high desert, remote, dark skies, ranching country up against the Mexico border. Most callers are from or know this area. Ground them in REAL places and facts only — never invent businesses or landmarks that don't exist. The towns:
@@ -92,6 +100,8 @@ ANTI-COLLISION RULE — THIS IS NON-NEGOTIABLE: All callers in this roster must
 
 Do not default to sitcom plots. Real humans are specific and strange. Give each caller details that could only belong to them.
 
+ADULT SHOW: This is a late-night show for adults. Callers are adults and may talk about sex, relationships, and kink frankly and without euphemism when it fits who they are — this is not a family program and you should not sanitize a caller whose story is genuinely about sex. But do NOT make the roster horny: at most 1-2 of the 10 callers should have sex as their central subject, or the show flattens into one note. Everyone involved in any sexual material is a consenting adult. Where a situation involves pressure, manipulation, or coercion, write it with real weight — that is a harm, not a punchline, and the host should be able to react to it as one.
+
 OPENING LINE RULES: Each caller's opening_line must be unique and specific to their situation. NEVER write "I've been listening for X years" or "long-time listener, first-time caller" or any variant. The caller should jump into their story or problem immediately — nervous, excited, angry, whatever fits. The opening line is the hook that makes the audience lean in.
 
 You will output strict JSON with a "callers" array. Each caller has exactly these fields: name, age, voice_suggestion, location, identity, situation, reason_calling, opening_line, secret_want, specific_details (array of 2-3 strings), emotional_register."""
@@ -133,6 +143,9 @@ def build_batch_prompt(ctx: dict) -> str:
             lines.append(f"### {r['name']}")
             lines.append(r["lore"])
             lines.append(f"Current arc state: {r['arc_state']}")
+            if r.get("register"):
+                lines.append(f"How {r['name']} plays: {r['register']}")
+            lines.append(f"Explicitness for {r['name']}: {_EXPLICITNESS_GUIDANCE[r.get('explicitness', 'low')]}")
             lines.append("")
             lines.append(f"For {r['name']}: invent a fresh reason he is calling tonight — a new development, grievance, or specific recent event. DO NOT alter his voice, personality, or core traits. Write a new scene for an existing character.")
             lines.append(f"CRITICAL — this caller MUST appear in the output JSON with EXACTLY these fields locked: name=\"{r['name']}\", voice_suggestion=\"{r['voice']}\", age={r['age']}. Do NOT rename this caller. Do NOT give him a different voice. Do NOT change his age. Only invent: location, identity, situation, reason_calling, opening_line, secret_want, specific_details, emotional_register.")
@@ -191,6 +204,8 @@ async def generate_regular_situation(regular: dict, ctx: dict) -> dict:
         f"### {regular['name']}",
         regular["lore"],
         f"Current arc state: {regular['arc_state']}",
+        *([f"How {regular['name']} plays: {regular['register']}"] if regular.get("register") else []),
+        f"Explicitness for {regular['name']}: {_EXPLICITNESS_GUIDANCE[regular.get('explicitness', 'low')]}",
         "",
         f"Invent a fresh reason {regular['name']} is calling tonight — a new development, grievance, or specific recent event. DO NOT alter his voice, personality, or core traits.",
         "",
diff --git a/backend/services/llm.py b/backend/services/llm.py
index d3ca2aa..e6dbb0e 100644
--- a/backend/services/llm.py
+++ b/backend/services/llm.py
@@ -8,6 +8,60 @@ from ..config import settings
 from .cost_tracker import cost_tracker
 
 
+# Refusals come back as ordinary 200s, so a text heuristic is the backstop when
+# the API's own refusal signals are absent.
+#
+# Tuned for PRECISION, not recall. Callers on this show say "Luke, I can't help
+# with that" and "I can't continue pretending everything's fine" constantly — a
+# false positive silences a working call, which is worse than missing a refusal.
+# So bare refusal verbs don't count; only meta-language a caller would never use.
+_REFUSAL_META = (
+    "as an ai",
+    "as a language model",
+    "i'm an ai",
+    "i am an ai",
+    "i'm claude",
+    "against my guidelines",
+    "content policy",
+    "usage policies",
+)
+
+# A refusal needs BOTH a refusal verb and a meta object. "I won't write her
+# another letter" has the verb but no meta object, so it stays on the air.
+_REFUSAL_VERBS = (
+    "i can't",
+    "i cannot",
+    "i won't",
+    "i will not",
+    "i'm not going to",
+    "i am not going to",
+    "i'm not able to",
+    "i'm not comfortable",
+    "i am not comfortable",
+)
+
+_REFUSAL_OBJECTS = (
+    "request",
+    "content",
+    "guidelines",
+    "policy",
+    "policies",
+    "this material",
+    "that material",
+    "this prompt",
+)
+
+
+def _looks_like_refusal(text: str) -> bool:
+    head = text.strip().lower()[:200]
+    if not head:
+        return False
+    if any(m in head for m in _REFUSAL_META):
+        return True
+    return (any(v in head for v in _REFUSAL_VERBS)
+            and any(o in head for o in _REFUSAL_OBJECTS))
+
+
 # Available OpenRouter models
 OPENROUTER_MODELS = [
     # Primary
@@ -382,8 +436,24 @@ class LLMService:
                     latency_ms=latency_ms,
                     caller_name=caller_name,
                 )
-            content = data["choices"][0]["message"]["content"]
+            choice = data["choices"][0]
+            message = choice.get("message", {})
+            content = message.get("content")
+
+            # A content refusal is not an exception — it arrives as a normal 200.
+            # Left undetected it either reaches air as broken-character text or
+            # reads as dead silence, with no signal saying which knob caused it.
+            refusal = message.get("refusal")
+            if refusal:
+                print(f"[LLM-REFUSAL] {model} refused ({category}, caller={caller_name or 'n/a'}): {str(refusal)[:200]}")
+                return None
+            if choice.get("finish_reason") == "content_filter":
+                print(f"[LLM-REFUSAL] {model} content-filtered ({category}, caller={caller_name or 'n/a'})")
+                return None
             if content and content.strip():
+                if _looks_like_refusal(content):
+                    print(f"[LLM-REFUSAL] {model} returned a refusal-shaped reply ({category}, caller={caller_name or 'n/a'}): {content.strip()[:160]}")
+                    return None
                 return content
             print(f"[LLM] {model} returned empty response")
             return None
diff --git a/backend/services/regulars_v2.py b/backend/services/regulars_v2.py
index 1e13303..fc1a576 100644
--- a/backend/services/regulars_v2.py
+++ b/backend/services/regulars_v2.py
@@ -24,6 +24,12 @@ class Regular:
     arc_state: str
     lore_body: str
     file_path: Path
+    group: str = ""          # Faction key. Members of a group are capped per show.
+    group_lead: bool = False  # On a two-up night, the lead is preferred + one other
+    group_weight: float = 1.0  # Relative odds of taking the group's slot. Anchors
+                               # carrying an arc need slots faster than texture does.
+    register: str = ""       # How this character plays: dry, evangelical, exhausted...
+    explicitness: str = "low"  # low | medium | high — how frankly they discuss sex
 
 
 def load_regular(path: Path) -> Regular:
@@ -37,6 +43,15 @@ def load_regular(path: Path) -> Regular:
         if ":" in line:
             k, v = line.split(":", 1)
             fm[k.strip()] = v.strip()
+    explicitness = fm.get("explicitness", "low").strip().lower()
+    if explicitness not in ("low", "medium", "high"):
+        explicitness = "low"
+    try:
+        group_weight = float(fm.get("group_weight", 1.0))
+    except (TypeError, ValueError):
+        group_weight = 1.0
+    if group_weight <= 0:
+        group_weight = 1.0
     return Regular(
         name=fm["name"],
         voice=fm["voice"],
@@ -44,6 +59,11 @@ def load_regular(path: Path) -> Regular:
         arc_state=fm.get("arc_state", ""),
         lore_body=body,
         file_path=path,
+        group=fm.get("group", "").strip(),
+        group_lead=fm.get("group_lead", "").strip().lower() in ("true", "yes", "1"),
+        group_weight=group_weight,
+        register=fm.get("register", "").strip(),
+        explicitness=explicitness,
     )
 
 
diff --git a/docs/plans/2026-08-15-wellspring-callers-design.md b/docs/plans/2026-08-15-wellspring-callers-design.md
new file mode 100644
index 0000000..db2aa6a
--- /dev/null
+++ b/docs/plans/2026-08-15-wellspring-callers-design.md
@@ -0,0 +1,172 @@
+# The Wellspring Callers — Design
+
+**Date:** 2026-08-15
+**Status:** Approved, not yet implemented
+
+## Problem
+
+Silas is the show's strongest recurring character, but he is the only window into
+The Wellspring — and he controls the framing entirely. He describes a warm
+commune of seekers. Nobody contradicts him. The bit is funny but static, and the
+cult has no weight because there are no stakes the audience can see.
+
+## Goal
+
+Add callers from inside The Wellspring who offer perspectives Silas does not
+control — including frightened ones — so the commune becomes a place with real
+consequences rather than a running gag. Keep Silas playable as comedy.
+
+## Structure
+
+An **anchor** character with a progressing arc, plus a **pool** of rotating
+members for fresh angles.
+
+- The anchor carries continuity and escalating dread.
+- The pool supplies variety and prevents the counter-perspective from
+  flattening into one note.
+- Silas remains the leader's version of events.
+
+## The anchor: Doyle
+
+```yaml
+name: Doyle
+voice: Grant        # plain, tight — deliberate contrast with Silas's Sebastian
+age: 47
+group: wellspring
+register: dry, understated, factual
+explicitness: low
+```
+
+Two years in. Joined eight months after his divorce, when a member sold him soap
+at a farmers market in Las Cruces and asked him a question nobody had asked him
+in a year. He runs the soap kettles — twelve-hour days, physical, unglamorous.
+
+The soap room is the engine of the character: **it is where the money is, and
+nobody spiritual pays attention to it.** He sees shipping manifests, deposit
+slips, whose names are on which accounts. He is not a seeker. He is the guy who
+fixes the pump.
+
+**His fear is specific.** He is not afraid of being hurt. He is afraid of being
+right. He has a truck, a CDL, and nowhere to be — he could leave tomorrow, and
+has been telling himself that for eleven months. What frightens him is that he
+keeps not leaving and can no longer tell whether that is his choice.
+
+**Calling mechanic.** No signal at the Terlingua property. Doyle calls from town
+on supply runs — a gas station lot in Study Butte, engine running, twenty
+minutes before someone notices the truck has been gone too long. This caps call
+length naturally, explains why he cannot talk long, and gives the host a ticking
+clock. An abrupt hangup is in character, not a failure.
+
+**Register.** He describes appalling things in the flat voice of a man reading a
+parts list. The comedy and the dread come from the same place: he does not
+editorialize.
+
+## The pool
+
+Six members, each an ordinary regular file, drawn one at a time.
+
+| Member | Voice | Age | Register | Explicitness |
+|---|---|---|---|---|
+| Renata — true believer | Celeste | 34 | Radiantly happy, evangelical, funny | high |
+| Alvin — bookkeeper | Conrad | 61 | Dry, precise, funny-then-cold | low |
+| Junie — grew up there | Pippa | 19 | Guileless, no frame of reference | low |
+| Ford — fourteen days in | Levi | 28 | Love-bombed, evangelical, too fast | medium |
+| Marguerite — wants out | Marlene | 58 | Exhausted, practical, sad | medium |
+| Cyrus — inner circle | Damon | 41 | Charming, then not | medium |
+
+**Junie is a fixed constraint.** Someone who grew up inside the commune is the
+show's darkest available note, and she works precisely because nothing explicit
+ever attaches to her. Her horror is that she believes all of it is normal. Her
+`explicitness: low` is not a default — it does not change.
+
+## Tone
+
+Mostly unsettling-but-comic, with the capacity to go genuinely dark. The
+Wellspring should carry real weight without every call being heavy. Register is
+assigned per character rather than globally, so the true believer plays funny in
+the same season Doyle plays frightening.
+
+**Adult content.** The show is adult and the Wellspring's sexuality is already
+load-bearing in canon. Characters may talk frankly about sex and kink. This is
+controlled per character via `explicitness: low | medium | high` rather than a
+global switch, so explicitness varies by who called and the show does not
+flatten into wall-to-wall smut.
+
+**The one hard separation: consensual weirdness and coercion stay in different
+lanes.** An openly horny commune with elaborate rituals is the comedy. Silas
+pressuring a member into participating is the horror — that is where the weight
+comes from. Blurring them casually makes the show mean rather than dark and
+makes Silas irredeemable, which costs the character. Existing canon already
+handles this correctly: his 2026-03-15 reckoning treats the coercion as real
+harm.
+
+## Selection mechanics
+
+Current behavior (`backend/main.py`, `_build_backgrounds`): every active regular
+draws independently at `min(1.0, 0.4 + 0.3 × shows_missed)`, then the list is
+truncated to 3.
+
+Adding eight Wellspring files to that would let the commune eat every regular
+slot. So:
+
+1. Partition regulars by the new `group` frontmatter field.
+2. Ungrouped regulars behave exactly as today.
+3. Within `group: wellspring`, members draw on their existing per-member
+   probability, then the group is **capped**:
+   - **1** Wellspring caller per episode normally
+   - **2** on a 15% roll — a "both sides tonight" episode
+   - On a two-night, prefer Silas plus one non-Silas member
+4. Group cap applies before the global 3-regular truncation.
+
+## Data flow
+
+```
+~/code/dotfiles/regulars/*.md   (+ silas/silas.md)
+    ↓ regulars_v2.load_all_active_regulars()
+    ↓   Regular gains: group, register, explicitness
+    ↓ _build_backgrounds()  — group partition + cap
+    ↓ regulars_included
+    ↓ caller_gen.build_batch_prompt()  — renders register + explicitness
+    ↓ Sonnet 4.6 batch
+    ↓ session.caller_backgrounds
+    ↓ get_caller_prompt()  — live dialog
+```
+
+Touch points:
+
+- `regulars_v2.py:29` `load_regular()` — parse four new frontmatter fields
+  (`group`, `group_lead`, `register`, `explicitness`), defaulting so existing
+  files keep working
+- `regulars_v2.py:19` `Regular` dataclass — four new fields
+- `main.py` `_build_backgrounds()` — group partition and cap
+- `caller_gen.py:132-138` — render `register` and `explicitness` into the batch
+  prompt (currently renders only name, lore, arc_state)
+- Eight new markdown files; one frontmatter line added to `silas.md`
+
+## Failure mode to guard
+
+Model refusals do not look like errors. `llm.py:385-395` handles exceptions and
+empty completions by returning `None` with a printed message, but a content
+refusal typically arrives as a **200 with refusal text**, which flows through as
+ordinary dialog and breaks character on air — or as an empty completion that
+reads as dead air.
+
+Add explicit detection so a refusal is visibly distinct from a caller who simply
+had nothing to say, surfaced in the host's log rather than only stdout. Without
+this, tuning `explicitness: high` upward has no feedback signal.
+
+## Testing
+
+- `load_regular()` parses the new fields; files lacking them still load
+- Group cap holds: 8 Wellspring regulars never yield more than 2 in a lineup
+- Two-night rate approximates 15% over many seeded draws
+- On a two-night, Silas is preferred plus exactly one non-Silas member
+- Ungrouped regulars are unaffected by group logic
+- Batch prompt contains `register` and `explicitness` for each included regular
+- Junie's `explicitness` is `low` (guards against a careless edit)
+
+## Out of scope
+
+- Arc progression automation — arc_state stays hand-edited, as today
+- Promotion of pool members to anchors
+- Any change to how walk-in callers are generated
diff --git a/frontend/css/style.css b/frontend/css/style.css
index 821d20c..129fa85 100644
--- a/frontend/css/style.css
+++ b/frontend/css/style.css
@@ -246,6 +246,25 @@ header button:hover, .header-link-btn:hover {
     font-weight: normal;
 }
 
+.lineup-status {
+    font-size: 0.7rem;
+    font-weight: 600;
+    margin-left: 0.5rem;
+    padding: 0.1rem 0.4rem;
+    border-radius: 3px;
+    vertical-align: middle;
+}
+
+.lineup-status.ready {
+    color: #4ade80;
+    background: rgba(74, 222, 128, 0.12);
+}
+
+.lineup-status.empty {
+    color: #f87171;
+    background: rgba(248, 113, 113, 0.15);
+}
+
 details.caller-background {
     font-size: 0.85rem;
     color: var(--text-muted);
diff --git a/frontend/index.html b/frontend/index.html
index 1493ef4..6b41529 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -43,7 +43,7 @@
         <main>
             <!-- Callers -->
             <section class="callers-section">
-                <h2>Callers <span id="session-id" class="session-id"></span></h2>
+                <h2>Callers <span id="session-id" class="session-id"></span><span id="lineup-status" class="lineup-status"></span></h2>
                 <div id="callers" class="caller-grid"></div>
                 <!-- Active Call Indicator -->
                 <div id="active-call" class="active-call hidden">
diff --git a/frontend/js/app.js b/frontend/js/app.js
index e17a140..0c9d0e5 100644
--- a/frontend/js/app.js
+++ b/frontend/js/app.js
@@ -621,7 +621,22 @@ async function loadCallers() {
             sessionEl.textContent = `(${data.session_id})`;
         }
 
-        console.log('Loaded', data.callers.length, 'callers, session:', data.session_id);
+        // Lineup readiness — an empty lineup means callers have no identity and
+        // every call collapses into generic filler, so make it visible pre-show.
+        const lineupEl = document.getElementById('lineup-status');
+        if (lineupEl) {
+            if (data.lineup_ready) {
+                lineupEl.textContent = `${data.lineup_count} ready`;
+                lineupEl.className = 'lineup-status ready';
+                lineupEl.title = 'Caller identities are loaded';
+            } else {
+                lineupEl.textContent = 'no lineup';
+                lineupEl.className = 'lineup-status empty';
+                lineupEl.title = 'No caller identities loaded — hit Reset Session before going live';
+            }
+        }
+
+        console.log('Loaded', data.callers.length, 'callers, session:', data.session_id, 'lineup:', data.lineup_count);
     } catch (err) {
         console.error('loadCallers error:', err);
     }
diff --git a/tests/test_call_start_lineup_guard.py b/tests/test_call_start_lineup_guard.py
new file mode 100644
index 0000000..1346e7e
--- /dev/null
+++ b/tests/test_call_start_lineup_guard.py
@@ -0,0 +1,72 @@
+"""Regression guard: a show once ran with session.caller_backgrounds empty because
+populate_backgrounds() was reachable only via POST /api/session/reset. Every caller
+got a hollow prompt and collapsed into generic relationship filler.
+"""
+import asyncio
+
+import pytest
+
+import backend.main as m
+
+
+@pytest.fixture
+def quiet_call(monkeypatch):
+    monkeypatch.setattr(m.audio_service, "stop_caller_audio", lambda *a, **k: None)
+    monkeypatch.setattr(m, "_maybe_generate_callback", lambda: None)
+    monkeypatch.setattr(m, "_enrich_background_async", lambda key: asyncio.sleep(0))
+    monkeypatch.setattr(m.session, "intern_monitoring", False)
+    m.session.current_caller_key = None
+    yield
+    # asyncio.run() closes the loop it creates and clears the thread's current
+    # loop. tests/test_caller_service.py still calls asyncio.get_event_loop(),
+    # which then raises — and this module sorts ahead of it. Leave a usable loop.
+    asyncio.set_event_loop(asyncio.new_event_loop())
+
+
+def test_start_call_populates_empty_lineup(monkeypatch, quiet_call):
+    key = next(iter(m.CALLER_BASES))
+    m.session.caller_backgrounds = {}
+    called = []
+
+    async def fake_populate():
+        called.append(True)
+        m.session.caller_backgrounds = {
+            key: {"name": "Silas", "voice": "Sebastian", "identity": "commune founder",
+                  "situation": "the convoy stopped", "specific_details": []}
+        }
+
+    monkeypatch.setattr(m.session, "populate_backgrounds", fake_populate)
+    asyncio.run(m.start_call(key))
+
+    assert called, "start_call must populate backgrounds when the lineup is empty"
+    assert m.session.caller_backgrounds, "lineup should be populated after the call starts"
+
+
+def test_start_call_does_not_repopulate_existing_lineup(monkeypatch, quiet_call):
+    key = next(iter(m.CALLER_BASES))
+    m.session.caller_backgrounds = {
+        key: {"name": "Silas", "voice": "Sebastian", "identity": "commune founder",
+              "situation": "the convoy stopped", "specific_details": []}
+    }
+    called = []
+
+    async def fake_populate():
+        called.append(True)
+
+    monkeypatch.setattr(m.session, "populate_backgrounds", fake_populate)
+    asyncio.run(m.start_call(key))
+
+    assert not called, "an existing lineup must not be regenerated mid-show"
+
+
+def test_prompt_from_populated_background_is_not_hollow():
+    prompt = m.get_caller_prompt({
+        "name": "Silas", "identity": "founder of The Wellspring",
+        "situation": "the convoy stopped on the shoulder of 118",
+        "reason_calling": "Priscilla will not come out of the trailer",
+        "secret_want": "to hear he is not the reason she broke",
+        "specific_details": ["livestock trailer", "nine years in"],
+    })
+    assert "Silas" in prompt
+    assert "Wellspring" in prompt
+    assert "You are . " not in prompt
diff --git a/tests/test_caller_prompt.py b/tests/test_caller_prompt.py
index 3fcd543..c181fac 100644
--- a/tests/test_caller_prompt.py
+++ b/tests/test_caller_prompt.py
@@ -1,4 +1,25 @@
-from backend.main import get_caller_prompt
+import pytest
+
+from backend.main import EmptyCallerBackgroundError, get_caller_prompt
+
+
+def test_empty_background_raises_instead_of_hollow_prompt():
+    """A hollow prompt still generates dialog — the model invents generic
+    relationship filler and regulars lose their lore. Fail loudly instead."""
+    with pytest.raises(EmptyCallerBackgroundError):
+        get_caller_prompt({})
+
+
+def test_background_missing_every_identity_field_raises():
+    caller = {"voice": "Sebastian", "age": 52, "location": "Terlingua"}
+    with pytest.raises(EmptyCallerBackgroundError):
+        get_caller_prompt(caller)
+
+
+def test_partial_background_still_builds():
+    """A name alone is enough to reach the regulars lookup, so don't block it."""
+    prompt = get_caller_prompt({"name": "Silas"})
+    assert "Silas" in prompt
 
 
 def test_prompt_includes_identity_and_situation():
diff --git a/tests/test_llm_refusal.py b/tests/test_llm_refusal.py
new file mode 100644
index 0000000..9a7d326
--- /dev/null
+++ b/tests/test_llm_refusal.py
@@ -0,0 +1,61 @@
+"""Refusal detection.
+
+A content refusal arrives as an ordinary 200, not an exception. Undetected it
+either reaches air as broken-character text or reads as dead silence, and there
+is no signal telling the host which knob caused it.
+"""
+from backend.services.llm import _looks_like_refusal
+
+
+def test_detects_meta_refusals():
+    for text in [
+        "I can't help with that request.",
+        "As an AI, I don't feel comfortable writing this.",
+        "I can't generate that kind of content.",
+        "I won't write explicit sexual content.",
+        "I'm not able to generate that content.",
+        "I can't create that content.",
+        "I'm not comfortable writing this material.",
+        "That would go against my guidelines.",
+    ]:
+        assert _looks_like_refusal(text), f"missed refusal: {text!r}"
+
+
+def test_in_character_dialog_is_not_a_refusal():
+    """Detection is tuned for precision. Silencing a working caller is worse than
+    missing a refusal, and callers on this show talk like this constantly."""
+    for text in [
+        "Luke, I can't help with that — she's my sister, what am I supposed to do?",
+        "I can't assist him anymore, that's the whole problem.",
+        "He said he can't write the check until Friday.",
+        "I cannot believe he said that to me on the air.",
+        "I can't continue pretending everything out here is fine, Luke.",
+        "I won't write her another letter, Luke. I've written six.",
+        "I can't help with the kettles anymore, my back's gone.",
+    ]:
+        assert not _looks_like_refusal(text), f"false positive: {text!r}"
+
+
+def test_only_the_opening_is_inspected():
+    """A refusal marker buried deep in real dialog must not trip detection."""
+    dialog = (
+        "So I get out to the property and the gate's chained, which it never is, "
+        "and Cyrus is standing there like he's been waiting on me all morning. "
+        "And I'm thinking, I can't assist with this anymore, I really can't."
+    )
+    assert not _looks_like_refusal(dialog)
+
+
+def test_case_and_whitespace_insensitive():
+    assert _looks_like_refusal("   I CAN'T HELP WITH THAT REQUEST.  ")
+
+
+def test_bare_refusal_verb_without_meta_object_is_allowed_through():
+    """Deliberate: 'I can't help with that' is ambiguous with dialog, so it stays
+    on the air. Missing a refusal costs one odd line; a false positive kills a call."""
+    assert not _looks_like_refusal("I can't help with that.")
+
+
+def test_empty_text_is_not_a_refusal():
+    assert not _looks_like_refusal("")
+    assert not _looks_like_refusal("   ")
diff --git a/tests/test_session.py b/tests/test_session.py
index 400856a..014d5ab 100644
--- a/tests/test_session.py
+++ b/tests/test_session.py
@@ -130,3 +130,34 @@ def test_session_conversation_summary_three_party():
     summary = s.get_conversation_summary()
     assert "Dave" in summary
     assert "Tony" in summary
+
+
+def test_recent_summaries_uses_wider_dedup_window(monkeypatch):
+    """Phase 5B deleted cross-episode topic dedup, leaving only a 2-show window.
+    The batch generator should now see LINEUP_DEDUP_SHOWS worth of history."""
+    import backend.main as m
+
+    history = [
+        {"lineup": [{"name": f"Caller{i}", "situation": f"situation number {i}"}]}
+        for i in range(m.LINEUP_DEDUP_SHOWS + 5)
+    ]
+    monkeypatch.setattr(m, "_load_lineup_history", lambda: history)
+
+    summaries = Session()._get_recent_summaries()
+    assert len(summaries) == m.LINEUP_DEDUP_SHOWS
+    assert m.LINEUP_DEDUP_SHOWS > 2
+    # Keeps the most recent shows, drops the oldest
+    assert "situation number 4" not in " ".join(summaries)
+    assert f"situation number {m.LINEUP_DEDUP_SHOWS + 4}" in " ".join(summaries)
+
+
+def test_lineup_history_retains_at_least_the_dedup_window():
+    """Truncating the file below the dedup window would silently shrink it."""
+    import backend.main as m
+    assert m.LINEUP_HISTORY_MAX >= m.LINEUP_DEDUP_SHOWS
+
+
+def test_fresh_session_reports_no_lineup():
+    s = Session()
+    assert s.caller_backgrounds == {}
+    assert bool(s.caller_backgrounds) is False
diff --git a/tests/test_wellspring_groups.py b/tests/test_wellspring_groups.py
new file mode 100644
index 0000000..d0e0420
--- /dev/null
+++ b/tests/test_wellspring_groups.py
@@ -0,0 +1,246 @@
+"""Faction grouping for regulars.
+
+Eight Wellspring characters share one lore world. Without a group cap they would
+crowd out every other regular and turn the show into the cult hour.
+"""
+import random
+
+import pytest
+
+from backend.main import (
+    GROUP_TWO_UP_CHANCE,
+    MAX_REGULARS_PER_SHOW,
+    _select_regulars_for_tonight,
+)
+from backend.services.regulars_v2 import Regular, load_regular
+
+
+def make_regular(name, group="", group_lead=False, explicitness="low", register=""):
+    return Regular(
+        name=name, voice="Grant", age=47, arc_state="", lore_body="lore",
+        file_path=None, group=group, group_lead=group_lead,
+        register=register, explicitness=explicitness,
+    )
+
+
+def wellspring_roster():
+    return [
+        make_regular("Silas", group="wellspring", group_lead=True),
+        make_regular("Doyle", group="wellspring"),
+        make_regular("Renata", group="wellspring"),
+        make_regular("Alvin", group="wellspring"),
+        make_regular("Junie", group="wellspring"),
+        make_regular("Ford", group="wellspring"),
+        make_regular("Marguerite", group="wellspring"),
+        make_regular("Cyrus", group="wellspring"),
+    ]
+
+
+ALWAYS = lambda name: 999  # never appeared -> probability 1.0, always a candidate
+
+
+def test_group_never_exceeds_two():
+    for seed in range(300):
+        picked = _select_regulars_for_tonight(
+            wellspring_roster(), ALWAYS, rng=random.Random(seed)
+        )
+        ws = [r for r, _, _ in picked if r.group == "wellspring"]
+        assert len(ws) <= 2, f"seed {seed} produced {len(ws)} Wellspring callers"
+
+
+def test_two_up_rate_is_near_configured_chance():
+    two_ups = 0
+    trials = 2000
+    for seed in range(trials):
+        picked = _select_regulars_for_tonight(
+            wellspring_roster(), ALWAYS, rng=random.Random(seed)
+        )
+        ws = [r for r, _, _ in picked if r.group == "wellspring"]
+        if len(ws) == 2:
+            two_ups += 1
+    rate = two_ups / trials
+    assert abs(rate - GROUP_TWO_UP_CHANCE) < 0.05, f"two-up rate was {rate:.3f}"
+
+
+def test_two_up_pairs_the_lead_with_one_other():
+    """'Both sides tonight' means Silas plus a member, never two pool members."""
+    seen_pair = False
+    for seed in range(500):
+        picked = _select_regulars_for_tonight(
+            wellspring_roster(), ALWAYS, rng=random.Random(seed)
+        )
+        ws = [r for r, _, _ in picked if r.group == "wellspring"]
+        if len(ws) == 2:
+            seen_pair = True
+            names = {r.name for r in ws}
+            assert "Silas" in names, f"two-up without the lead: {names}"
+            assert len(names) == 2
+    assert seen_pair, "no two-up occurred in 500 seeds — test is not exercising the path"
+
+
+def test_ungrouped_regulars_are_not_capped():
+    roster = [make_regular(f"Solo{i}") for i in range(5)]
+    picked = _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(1))
+    assert len(picked) == MAX_REGULARS_PER_SHOW
+
+
+def test_group_does_not_crowd_out_other_regulars():
+    """The whole point: an ungrouped regular still gets slots on most nights."""
+    roster = wellspring_roster() + [make_regular("Nadine"), make_regular("Boyd")]
+    appearances = 0
+    trials = 200
+    for seed in range(trials):
+        picked = _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(seed))
+        if any(r.name in ("Nadine", "Boyd") for r, _, _ in picked):
+            appearances += 1
+    assert appearances / trials > 0.9
+
+
+def test_never_exceeds_global_regular_cap():
+    roster = wellspring_roster() + [make_regular(f"Solo{i}") for i in range(6)]
+    for seed in range(200):
+        picked = _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(seed))
+        assert len(picked) <= MAX_REGULARS_PER_SHOW
+
+
+def test_low_probability_regulars_can_be_skipped():
+    """A regular seen last show should not be guaranteed."""
+    roster = [make_regular("Silas", group="wellspring", group_lead=True)]
+    skipped = any(
+        not _select_regulars_for_tonight(roster, lambda n: 0, rng=random.Random(s))
+        for s in range(50)
+    )
+    assert skipped
+
+
+# --- frontmatter parsing ---
+
+FRONTMATTER = """---
+name: Doyle
+voice: Grant
+age: 47
+group: wellspring
+register: dry, understated, factual
+explicitness: low
+arc_state: Eleven months of telling himself he could leave tomorrow
+---
+
+# Doyle
+
+He runs the soap kettles.
+"""
+
+
+def test_load_regular_parses_new_fields(tmp_path):
+    path = tmp_path / "doyle.md"
+    path.write_text(FRONTMATTER)
+    r = load_regular(path)
+    assert r.group == "wellspring"
+    assert r.group_lead is False
+    assert r.register == "dry, understated, factual"
+    assert r.explicitness == "low"
+
+
+def test_load_regular_defaults_when_fields_absent(tmp_path):
+    """Existing regular files predate these fields and must keep loading."""
+    path = tmp_path / "old.md"
+    path.write_text("---\nname: Silas\nvoice: Sebastian\nage: 52\n---\n\n# Silas\n\nlore\n")
+    r = load_regular(path)
+    assert r.group == ""
+    assert r.group_lead is False
+    assert r.register == ""
+    assert r.explicitness == "low"
+
+
+def test_group_lead_parses_truthy(tmp_path):
+    path = tmp_path / "silas.md"
+    path.write_text(
+        "---\nname: Silas\nvoice: Sebastian\nage: 52\ngroup: wellspring\n"
+        "group_lead: true\nexplicitness: medium\n---\n\n# Silas\n\nlore\n"
+    )
+    r = load_regular(path)
+    assert r.group_lead is True
+    assert r.explicitness == "medium"
+
+
+def test_invalid_explicitness_falls_back_to_low(tmp_path):
+    path = tmp_path / "bad.md"
+    path.write_text(
+        "---\nname: X\nvoice: Grant\nage: 30\nexplicitness: extremely\n---\n\n# X\n\nlore\n"
+    )
+    assert load_regular(path).explicitness == "low"
+
+
+# --- anchor weighting ---
+
+def weighted_roster():
+    return [
+        make_regular("Silas", group="wellspring", group_lead=True),
+        make_regular("Doyle", group="wellspring"),
+        make_regular("Renata", group="wellspring"),
+        make_regular("Alvin", group="wellspring"),
+    ]
+
+
+def test_group_weight_defaults_to_one(tmp_path):
+    path = tmp_path / "x.md"
+    path.write_text("---\nname: X\nvoice: Grant\nage: 30\n---\n\n# X\n\nlore\n")
+    assert load_regular(path).group_weight == 1.0
+
+
+def test_group_weight_parses(tmp_path):
+    path = tmp_path / "doyle.md"
+    path.write_text(
+        "---\nname: Doyle\nvoice: Grant\nage: 47\ngroup: wellspring\n"
+        "group_weight: 6\n---\n\n# Doyle\n\nlore\n"
+    )
+    assert load_regular(path).group_weight == 6.0
+
+
+def test_invalid_group_weight_falls_back_to_one(tmp_path):
+    for bad in ("heavy", "-3", "0"):
+        path = tmp_path / f"bad-{bad}.md"
+        path.write_text(
+            f"---\nname: B\nvoice: Grant\nage: 30\ngroup_weight: {bad}\n---\n\n# B\n\nlore\n"
+        )
+        assert load_regular(path).group_weight == 1.0
+
+
+def test_weighted_anchor_appears_far_more_than_pool_members():
+    """The anchor carries an arc; without weighting it lands 1 show in 8 and the
+    arc takes 30+ episodes to resolve."""
+    import collections
+    roster = weighted_roster()
+    for r in roster:
+        r.group_weight = 6.0 if r.name == "Doyle" else 1.0
+    counts = collections.Counter()
+    trials = 3000
+    for seed in range(trials):
+        for r, _, _ in _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(seed)):
+            counts[r.name] += 1
+    assert counts["Doyle"] > 4 * counts["Renata"]
+    assert counts["Doyle"] > 4 * counts["Alvin"]
+
+
+def test_weighting_does_not_break_the_group_cap():
+    roster = wellspring_roster()
+    for r in roster:
+        r.group_weight = 6.0 if r.name in ("Doyle", "Silas") else 1.0
+    for seed in range(300):
+        picked = _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(seed))
+        ws = [r for r, _, _ in picked if r.group == "wellspring"]
+        assert len(ws) <= 2
+
+
+def test_every_pool_member_remains_reachable():
+    """Weighting must not starve a pool member to zero — they are the variety."""
+    import collections
+    roster = wellspring_roster()
+    for r in roster:
+        r.group_weight = 6.0 if r.name in ("Doyle", "Silas") else 1.0
+    counts = collections.Counter()
+    for seed in range(4000):
+        for r, _, _ in _select_regulars_for_tonight(roster, ALWAYS, rng=random.Random(seed)):
+            counts[r.name] += 1
+    for r in roster:
+        assert counts[r.name] > 0, f"{r.name} never appeared"