murder-mystery-oneshot/storylines/natural-progression.md

# Natural Progression and Outcome Map

This is the DM-facing causal map for the night. It describes what happens without player intervention and how increasingly informed intervention changes the result.

## Guiding Principle

> **Doing nothing should generally produce the worst outcome. Engaging with the story should visibly change what survives, what escapes, and what the players learn.**

This is a rule of thumb, not a promise that every action is good. Killing the Guest without understanding the larger situation is allowed to be a plainly bad choice. The important thing is that it still changes the ending.

Solving Orenn's murder is also not enough by itself. The lockdown has already admitted Xarrul to the Material interior. The active threat is the body it intends to take during the midnight resealing window.

---

## Canonical Terms

### The Vacancy

The negotiated transfer between Xarrul and the Guest at the tear in the Deep Cellar's Old Work.

- It cannot begin while the lockdown blocks the Guest's Astral release. Midnight opens its single three-round window.
- The Guest willingly projects out of the changeling body.
- Xarrul projects into it.
- For three rounds, Xarrul, the Guest's projected spirit, and the vacant body are separate targets.
- If nobody intervenes, Xarrul takes the changeling body and the Guest is projected into the Astral Plane. The Guest does **not** become the spectral Host of the Inn.
- If the players destroy Xarrul during the transfer, the Guest returns empowered by Xarrul's planar imprint.

### The Hollowing

The forced replacement ritual used if the Guest is dead or otherwise unavailable.

- Xarrul abducts a living humanoid and brings the victim to the tear's containment circle.
- The ritual resembles the Vacancy visually: victim's spirit, empty body, and Xarrul become separately visible.
- Unlike the Guest, the victim has not consented and receives no bargain.
- Xarrul destroys the victim's projected spirit and silver cord, then keeps the empty body.
- The victim is never promised back. A Hollowing that finishes is murder followed by possession, not a hostage exchange.

The Hollowing gives Xarrul an ordinary mortal body. That is useful, but much less dangerous than a changeling body able to become anyone.

---

## Ending Tree at a Glance

```text
LOCKDOWN BEGINS
    |
    +-- Players do not affect the cellar or the factions
    |      |
    |      +-- Guest alive
    |      |      -> Vacancy succeeds
    |      |      -> Xarrul takes changeling body
    |      |      -> Guest is lost in Astral Plane
    |      |      -> pre-transfer compact expires
    |      |      -> Xarrul leaves secretly, or kills only exposed witnesses able to stop it
    |      |
    |      +-- Guest dead
    |             -> Xarrul abducts replacement
    |             -> Mags searches Deep Cellar alone and dies
    |             -> Hollowing succeeds
    |             -> Xarrul enters upstairs war in inferior mortal body
    |
    +-- Players help only the Guest
    |      -> destroy Xarrul during Vacancy
    |      -> empowered Guest returns
    |      -> Guest secretly cages Mags and takes her identity and Inn
    |
    +-- Players provide anti-Xarrul tools but no political solution
    |      -> loyal cultists try to rebind
    |      -> everyone else tries to destroy Xarrul Ethereally
    |      -> cult loyalists die; Xarrul dies if the planar pincer survives their sabotage
    |
    +-- Players provide tools and win a political solution
           |
           +-- Rebind Xarrul
           |      -> everyone can survive
           |      -> Xarrul becomes the Order's weapon again
           |      -> Nessa remains lost but the connection remains
           |
           +-- Bell-and-sigils seal
           |      -> everyone can survive
           |      -> Xarrul is trapped between planes
           |      -> Nessa remains lost but the connection remains
           |
           +-- Ethereal destruction
           |      -> Xarrul is permanently destroyed
           |      -> Nessa wakes
           |
           +-- Deliberately release Xarrul
                  -> party secures protection after the Guest's compact expires
                  -> party must fool, frame, or neutralize Mags
                  -> Xarrul leaves disguised in changeling body
```

Any political plan can degrade into casualties. If the disagreement consumes too many rounds or kills the people carrying the anti-ethereal tools, Xarrul wins.

---

## Passive Default: Nobody Enters the Cellar

The PCs may investigate nothing, or they may not be present at the Nether Inn at all. In either case, no outsider enters the cellar and no one interferes with Xarrul and the Guest.

### During the Lockdown

- Xarrul guards the Guest, the anti-fiend tools and the midnight transfer site below; there is no crossing progress to tend.
- Upstairs, it uses stolen voices, true accusations, waking visions, and altered memories to sharpen the existing conflict without killing anyone itself.
- The assassins and cultists interpret every new incident as enemy action.
- Mags can suppress individual confrontations, but she cannot restore trust.
- By the final portion of the lockdown, the factions are exhausted, divided, and one failed accusation away from lethal violence.
- The compact permits Xarrul to kill Orenn but nobody else until the exchange finishes, except direct defense against binding, banishment, or destruction. It does not protect the factions from one another.

Use this relative clock if the players need visible escalation:

| Time | Default event upstairs | Xarrul below |
|---|---|---|
| **T−90 minutes** | A fresh, true accusation is heard in the wrong voice; Kael openly blames Haddon. | Checks Cell One and the tear from the Ethereal Plane. |
| **T−60 minutes** | A last-minute memory edit makes one NPC sincerely accuse the wrong speaker; Mags prevents the first drawn weapon. | Weakens the cell ward and confirms the Guest is ready. |
| **T−30 minutes** | Rennt or Kael turns a shove into a lethal attack; Sevra and the cultists choose sides. Mags or the PCs can still prevent the first faction death. | Opens Cell One and moves the willing Guest toward the Old Work. The lower alarm fires, but Mags is occupied upstairs. |
| **T−10 minutes** | A rescue or retaliation widens the fight. Keep Haddon or Essek able to recognize the danger if the transfer is exposed. | Positions the Guest and watches the prepared transfer site; the Vacancy still cannot begin. |
| **Midnight** | The shell lapses. Anyone who noticed the lower alarm has one last chance to reach the Old Work. | Begins the three-round Vacancy. Afterward, leaves secretly or removes exposed anti-fiend threats and witnesses. |

Move the entries earlier when the party exposes faction secrets without mediating, and later when they produce credible evidence of the common threat.

The default upstairs conflict is not one neat battle with predetermined sides. It is a sequence of accusations, attacks, rescues, and revenge strikes. Xarrul cannot kill anyone itself before the exchange finishes, but the factions can kill one another. Keep enough survivors for the players' choices and, if the transfer is exposed, the recognition beat.

### The Uninterrupted Vacancy

No PC needs to free the Guest. Xarrul and the Guest planned this together.

The lockdown has already made Xarrul fully capable of manifesting inside the Inn. Before midnight it opens Cell One from the Ethereal side and escorts the willing Guest to the tear. They cannot begin while the shell blocks the Guest's Astral destination. The moment the shell lapses, returning ward-power opens the three-round Vacancy window inside the containment circle.

Without outside hands, Xarrul wins automatically:

1. The Guest leaves its body.
2. Xarrul takes the changeling body.
3. The Guest's spirit is pushed into the Astral Plane and abandoned there.
4. Xarrul retains its own abilities and gains the changeling's Shapechanger ability.

This is Xarrul's best possible result. It can now become Mags, a cultist, a guild blade, a city official, or anyone else whose face it has studied.

### After the Compact Expires

Delivering the Guest Astral completes the exchange and ends its restraint on Xarrul. What Xarrul does next depends on exposure, not a fixed appetite for massacre.

If nobody witnessed the Vacancy, Xarrul chooses an innocuous face, joins the frightened patrons as the doors release, and leaves. Contradictory living witnesses who never saw the new body are better cover than a tavern full of corpses.

If the transfer was exposed, the surviving patrons know too much and may already be moving anti-fiend tools against the new vessel. Xarrul then removes the people who can identify or stop it.

If it enters the hall openly:

1. The remaining cultists feel the old binding react without accepting a command. They finally understand that they never regained control.
2. Haddon or Essek recognizes Xarrul's signature and identifies it as the thing that killed Orenn.
3. They tell Mags. The faction fight stops for one brief, terrible moment.
4. Everyone turns on Xarrul.
5. They can see pieces of the problem—Essek may perceive it and Mags may ring the bell—but sight alone cannot cross the planar boundary, and they cannot pin Xarrul consistently after the faction war. Mags and Haddon each possess a reserve dose of Oil of Etherealness, but neither has the ten uninterrupted minutes needed to apply it after this revelation.
6. Xarrul uses Ethereal Jaunt every round, kills the few people who can perceive or hurt it first, and dismantles the rest.

Its cleanup priority is practical:

1. Anyone currently Ethereal or carrying Veilhook Salt.
2. Whoever reaches for the iron bell or restored sigils.
3. Haddon, who can identify, bind and later report it.
4. Essek, who understands its planar nature.
5. Mags and Sevra, then the remaining witnesses.

The defenders possess fragments of a counter, not the preparation and coordination needed to hold Xarrul in one plane.

### Passive Ending

- Orenn is dead.
- The Guest is stranded in the Astral Plane.
- Xarrul has the changeling body and can move through the city wearing any face.
- If the transfer remained secret, the remaining divided patrons face no further attack from Xarrul; if it was exposed, those capable of identifying or stopping the new vessel may die.
- Nessa remains lost.
- Mother Vyre loses one local cell but does not know what left the tavern wearing its faces.
- Xarrul walks out after midnight with no living witness able to identify its chosen face.

This is the worst ending because Xarrul gains permanent embodiment and maximum concealment; the precise body count depends on whether the party exposed the transfer without stopping it.

---

## Bad Intervention: The Players Only Kill the Guest

This means the players kill the Guest in Cell One and take no effective action against Xarrul, the midnight vessel-working, or the upstairs pressure cooker.

### Immediate Effect

- The Guest's intelligence and testimony are lost.
- The Vacancy is no longer available as an easy opportunity to attack Xarrul.
- The Handler's Agent and Mourner fail their objectives; the Executioner succeeds.
- Xarrul loses the uniquely valuable changeling body.
- The exchange is now impossible, so the compact's temporary restraint ends immediately. Xarrul can kill directly rather than working through faction violence.
- The Guest's killer becomes Xarrul's first replacement-vessel target. Its warning to the Executioner was not a bluff.
- Mercy's call continues and points deeper. The call came from Xarrul and the rift, not from the Guest.

### The Abduction

Xarrul selects an isolated mortal body as a replacement. Prefer, in order:

1. A PC directly responsible for killing the Guest.
2. A vulnerable but useful NPC separated by the faction conflict.
3. A cultist whose body will let Xarrul approach the survivors without immediate suspicion.

The victim vanishes during one of Xarrul's manufactured distractions.

### Why Mags Goes Down Alone

- The disappearance is noticed.
- Twinkle's agitation, a disturbed lower ward, or Mags's private alarm confirms that someone entered the Deep Cellar.
- Haddon knows enough about the building's original containment to understand the direction, but Mags refuses to let the cultists enter her secret operation.
- She takes the black key and goes alone, intending to retrieve the missing person and keep the cells hidden.
- Xarrul kills her before beginning the Hollowing. It will not risk the owner of the house interrupting the transfer.

### The Hollowing

The victim is projected out of their body. Xarrul destroys the projected spirit and takes the body. There is no promise, safe return, or future rescue.

Afterward, Xarrul enters the ongoing upstairs conflict. The conclusion broadly resembles the passive ending, but Xarrul has an ordinary stolen body rather than a changeling body. The choice was bad and caused additional immediate harm, but it denied Xarrul its most dangerous long-term disguise.

---

## Narrow Intervention: The Players Only Help the Guest

“Help the Guest” means freeing it, bringing it to the tear in the Old Work, protecting its projected spirit, and destroying Xarrul during the Vacancy.

### Vacancy Result

- Xarrul is destroyed during the one moment when it cannot escape.
- The Guest reclaims its body.
- Xarrul's planar imprint burns out the suppressant and gives the Guest Ethereal Jaunt, Shadow Cloak, Voice Thief, and fragments of Xarrul's memories.
- Nessa's stolen vitality remains in the empowered Guest rather than returning to her. Nessa remains lost.

### The Guest Takes the Inn Quietly

The Guest is smarter about ownership than Xarrul is about witnesses. It does not challenge Mags in the main hall.

1. It uses Orenn's voice from below to lure Mags into the cellar alone.
2. It leads her to Cell One under the pretense that Orenn left something there or that the wards are failing.
3. It ambushes and imprisons her in its old cage.
4. It takes Mags's form and returns upstairs.
5. Wearing Mags's authority, it stops or redirects the faction conflict and keeps the Nether Inn.

If the players truly do nothing beyond helping the Guest kill Xarrul, they may leave believing Mags survived and retained the house. Discovering the exchange is a later consequence.

If they continue investigating, they can notice the false Mags, rescue the real one, support the Guest's claim openly, or trigger a succession fight.

---

## Tactical Intervention Without Political Agreement

The players discover or distribute Veilhook Salt, Oil of Etherealness, the silver mirror, the iron bell, or another meaningful defense, but fail to create agreement about what should happen to Xarrul.

When Xarrul appears, the room splits:

- **Haddon and Rennt** want Xarrul alive and rebound.
- **Sevra, Mags, and most unaffiliated defenders** want the murderer destroyed.
- **Dalla** supports rebinding until the conduit truth is exposed; afterward she refuses it.
- **Essek** supports ending Xarrul rather than returning it to the Order, if he believes anyone can protect him.

The cult is therefore not automatically one unified side. “The cultists die” normally means Haddon, Rennt, and anyone still loyal enough to help them sabotage the attack.

If the armed defenders retain an Ethereal attacker and enough strength after that internal fight, they maintain pressure on both planes and destroy Xarrul in the Ethereal Plane. Nessa wakes. If the Ethereal hunter falls or loses access before the final blow, Material defeat only triggers Deathless Slip; Xarrul escapes into the Ethereal interior, heals and turns the fight.

If the argument destroys the tools, their users, or the positioning needed to cover both planes, Xarrul wins instead.

---

## Political Resolutions

These endings require both the necessary tools and enough persuasion to make the room follow one plan. Failed persuasion does not merely close a dialogue option: it creates dissenters who may interfere, die, or hand Xarrul the opening it needs.

### Rebinding

The party convinces Mags, Sevra, Dalla, and the other defenders to let Haddon conduct the ritual.

- Everyone can survive.
- Xarrul is bound again.
- The Order regains its weapon and continues toward the Opening.
- Nessa remains lost, but her connection through Xarrul and Dalla still exists.
- The cult believes the Opening can eventually return her. That possibility is real; the price of the Opening remains catastrophic.

### Bell-and-Sigils Sealing

The party restores the foundation sigils, traps Xarrul in the binding circle, and rings the iron bell.

- Everyone can survive.
- Xarrul is sealed consciously between the Material and Ethereal planes.
- The Order does not regain direct control of it.
- The energetic connection to Dalla and Nessa remains intact.
- Nessa can potentially still be recovered later through the Opening or, preferably, through a safer method developed from the surviving research.

This is a genuine alternative to rebinding, not merely “leave Nessa lost forever.” It preserves the possibility of rescue without immediately returning Xarrul to Haddon.

### Ethereal Destruction

The party convinces enough of the room to cover both planes and pursue Xarrul wherever it shifts.

- Everyone can survive if nobody sabotages the planar pincer.
- Xarrul is permanently destroyed when reduced to 0 HP in the Ethereal Plane.
- The stored vitality returns through Dalla's conduit.
- Nessa wakes.

Haddon and Rennt may still resist. If that resistance removes the Ethereal hunter or breaks one side of the pincer, Xarrul can recover and win.

---

## Deliberately Siding With Xarrul

Xarrul does not need a massacre in order to escape. Once it has the changeling body, it can disguise itself and walk out through the front door after the lockdown lapses.

The Guest's compact restrains Xarrul's own killing only until the exchange finishes. If the players want guaranteed survival afterward—especially if their intervention will expose Xarrul's new body—they must secure a separate promise. Xarrul keeps it.

The real obstacle is Mags.

### Mags's Position

Mags will not let the doors open on an unresolved murder, and she will never knowingly allow Orenn's murderer to leave. The party must therefore do one of the following without turning the entire room against itself:

- **Frame someone else** convincingly enough that Mags accepts a false murderer.
- **Convince Mags that Xarrul did not act alone** and sacrifice the Guest or another accomplice as the actionable culprit.
- **Neutralize Mags quietly** through imprisonment, incapacitation, or manipulation of her Warden's Mark.
- **Replace or bypass her authority** long enough for disguised Xarrul to join the people leaving at midnight.

An open attack on Mags normally turns Sevra, Kael, Thera, and any surviving regulars against the party. This path should be a social and covert finale, not simply another combat.

### Successful Escape

- Xarrul takes the changeling body.
- The Guest is projected into the Astral Plane.
- Xarrul leaves in the face of someone permitted to walk out.
- It keeps any explicit promise protecting the room after the Guest's compact expires.
- If rescuing Nessa was included in the bargain, it later follows her tether and returns her.
- Mags remains framed, imprisoned, incapacitated, or convinced that someone else paid for Orenn's death.

Xarrul is not the cleverest creature in every room. The Guest conceived the better body-and-escape plan; Xarrul supplied the planar knowledge and power to make it possible.

---

## The Pressure Cooker as the Default Overlay

Faction war is the threatened consequence underneath every unresolved route. Before the Vacancy finishes, the compact keeps Xarrul from personally joining it lethally but does not protect the factions from one another.

- Without intervention, Xarrul's whispers bring the room into lethal conflict before midnight. It does not land or deliberately command the killing blows itself.
- A clear plan can pause it.
- Exposing the Order without controlling Sevra and Kael accelerates it.
- Attempting to destroy Xarrul without addressing Haddon and Rennt turns it into a three-sided fight.
- Severe casualties remove anti-Xarrul tools and can turn an otherwise successful plan into Xarrul's victory.

When evaluating an ending, ask two separate questions:

1. What did the party decide should happen to Xarrul?
2. Did they persuade enough people to let that happen?

---

## Outcome Ladder

This is not an objective moral ranking, but it is the intended progression of player impact.

| Engagement | Typical result |
|---|---|
| **None** | Xarrul gains changeling body and leaves unseen; exposed witnesses die only if they can identify or stop the new vessel |
| **Violent but uninformed** | Guest and replacement victim die; Mags dies; Xarrul escapes in an inferior body |
| **One-sided alliance with Guest** | Xarrul dies; Nessa remains lost; empowered Guest secretly takes the Inn |
| **Tactical preparation only** | Cult loyalists die; Xarrul is destroyed if the defenders keep an Ethereal hunter in the fight |
| **Preparation plus consensus to rebind** | Everyone survives; Xarrul and Nessa's connection remain under the Order's control |
| **Preparation plus consensus to seal** | Everyone survives; Xarrul contained; Nessa may still be recovered later |
| **Preparation plus consensus to destroy Ethereally** | Everyone survives; Xarrul permanently destroyed; Nessa wakes |
| **Deliberate bargain with Xarrul** | Disguised Xarrul escapes; survival after the Vacancy depends on what the party did to Mags and what promises they secured |

The propagated decisions are recorded in **[Ending Tree — Revisit List](ending-tree-revisit.md)**. For at-the-table pressure moves when a route becomes too easy, use the **[Complication Toolkit](complication-toolkit.md)**.