The Oath’s Other Clause
The Oath’s Other Clause
Read aloud
The Citadel is a city of warm stone, ring inside ring, all of it listening. The lift settles into the Deep Dock with a soft chime, and a boy with a brass gauge pinned to his coat looks up from a bench to read your faces. Behind him the dock bells begin to ring on their own, in a pattern that is almost a route signal and not quite.
Run the session
Cheat sheet
Objectives
- 1Decide who should be authorized to receive the recovered clause.
- 2Find the sealed vault and establish what its repair was meant to contain.
- 3Recover the second clause from the vault.
- 4Make the Concordat’s first decision about who gets to know what the founders wrote.
The clock
The Gate Closes has 6 segments. Tick it once for each failed council success check, once for each day beyond the third, and once if the party is seen entering the Old Gauge Run unescorted. At 6 segments, the Absolute reaches the vault first: the Vault fight starts with the Quenchers inside and the seal already cracked, and the Count gains one extra mark. At the end of the Act, advance the Count by 1 in addition to any extra mark. The Gate-Hall’s doors close at a fixed hour; establish the hour at the table and keep the deadline visible.
Scenes
- 0:00The Dock Hears First
- 0:45Five Votes, One Text
- 2:15The Quiet Gauge
- 3:45The Vault’s Broken Note
- 6:15The Choice of Audience
Cast
- Warden-Elder Isaura Vent-KeeperQuestgiver and ally
- High Archon Ottar Frost-BanePolitical obstacle
- Brannoch Slate-HandWitness and reluctant council voter
- Salk VordaCivic auditor and potential ally
The hook
Set the scene
Read the hook as the party arrives at the Deep Dock. The young gauge-bearer is a junior archivist and can direct the party to Isaura. The bells’ irregular pattern is a sensory warning and a thread to the wider mystery, not a code the party must solve. Isaura explains that the council is about to meet, asks the party to recover the older oath, and admits she has not seen the hidden wording. Establish The Gate Closes, a six-segment clock: tick it for each failed council success check, each day beyond the third, and if the party is seen entering the Old Gauge Run unescorted. Filling it means the Absolute reaches the vault first and adds one mark to the Count.
How Warden-Elder Isaura Vent-Keeper asks
Isaura requests a private meeting shortly after the party reaches the Deep Dock.
She is candid that she does not know the clause’s contents. She asks the party to secure the text before the Council Moot, then leaves the choice of disclosure to them. If the party declines or misses the Moot, she can still hold the text for them, but the political and time costs increase.
Rumours
Scenes
about 7.5 hours0:00
45 min
socialThe table is here
1. The Dock Hears First
The Hearth-Core Citadel’s Deep Dock, where warm stone sweats mineral moisture and brass instruments tremble faintly with each bell note.
The party reaches the Deep Dock as the bells sound an almost-familiar pattern. The junior archivist directs them to Isaura, who requests the recovery and explains the Gate Closes clock. Let the characters question the archivist and inspect the dock without making the bell pattern a mandatory puzzle.
NextIsaura escorts the party through the inner rings toward the Council Moot, while the bell pattern trails after them through the stone.
0:45
90 min
social
2. Five Votes, One Text
The Gate-Hall’s Council Moot, a warm circular chamber where five council voices compete beneath the measured tick of instruments.
The five votes that matter are High Archon Ottar Frost-Bane, Brannoch Slate-Hand, Salk Vorda, Aster, and Bragi. The party needs 3 of 5 votes to publish the clause or 2 of 5 to give it only to Isaura. Each vote is won by one success against that member’s DC; two failures against the same member lose that vote for the Moot. Ottar’s Persuasion DC is 20. Brannoch requires Insight followed by Persuasion . Salk’s Persuasion DC is 18. Aster can be persuaded with Persuasion or Medicine . Bragi’s Persuasion DC is 20. A Favor, Standing 3 or higher with the relevant faction, or lighting the Ember in the Gate-Hall grants Advantage on one check; the Floor Log from Act I grants Advantage on checks with Salk and Aster. If the party reaches Brannoch before the Moot, he may confess and can be persuaded to vote for publication with ; otherwise he votes against. Track failed council success checks against The Gate Closes.
NextWhatever the vote, the council’s attention shifts to the old gauge and the unsigned repair, sending the party toward the instrument galleries before the deadline tightens.
2:15
90 min
exploration
3. The Quiet Gauge
The Citadel’s instrument gallery and repair passages, where the heat thins, gauge needles click unevenly, and hidden metalwork seems to hum beneath the stone.
At the Quiet Gauge, a Intelligence (Investigation or Arcana) check traces the low readings to adjustments made by Brannoch. At the repair site, a Charisma (Persuasion) check with the craft-wardens or a Dexterity check using Smith’s Tools reveals that the repair was ordered from above and made to hold something in, not keep thieves out. The work dates to the Winter of Bells, within a generation of the oath’s founding. A Wisdom (Perception) check finds the newer panel concealing the Old Gauge Run staircase of founders’ stone. Entering it unescorted when seen advances the clock once. Other reasonable investigation, bribes, favors, or spells can reveal the same facts.
NextThe concealed founders’ staircase descends behind the newer panel, carrying the party away from the public halls and toward a door no current warden claims to have repaired.
3:45
150 min
combat
4. The Vault’s Broken Note
The founders’ vault, a 60-by-40-foot room of dark stone, sealed gauge cabinets, and a central lectern. A cracked wall opens behind the raiders.
The vault door opens with a Dexterity check using Smith’s Tools or with Isaura’s word. The chamber contains a lectern holding the oldest oath and sealed gauge cabinets that vent the Pressure Surge on initiative count 20. The Absolute’s raiding party arrives as a cold wind passes through the lectern. Run the Vault encounter, keeping the oath’s retrieval and the cabinets’ pressure hazard in view. When the Bell-Raiser falls to half its hit points, it sounds the first beat of the count. If the Gate Closes clock filled, begin with the Quenchers inside and the seal already cracked.
NextAs the ringing subsides, the oath’s surviving words become audible over the cooling metal, and the Ember’s light falls across a dull shard.
6:15
60 min
social
5. The Choice of Audience
The vault’s lectern and the warm corridor beyond it, where the surviving parchment smells of old resin and the metal shard begins to hold heat.
After the fight, the party retrieves and reads the oath. Hand them the incomplete clause only now: “The second clause. When the gauges fall by a third, let the keeper of the hearth sit in the seat and keep the beat as it was kept. When the keeper fails, let the line be cut at the heart, and let those who cut it bear the cold. Should neither be done, the count will keep itself, and what answers will hear the end. And if the count is answered, then let”. A Intelligence (Investigation) check confirms the final sentence was never finished. The party chooses to publish the text, give it only to Isaura, or return the vault to its sealed state. Resolve the corresponding Standing, Drift, and future access consequences, then award the Mantle-Forged Abyss-Plate and Oath-Cinder if the party completes the quest.
NextWith the clause entrusted, concealed, or shared, the party leaves the vault as two letters begin their journey toward the Citadel.
Behind it
What people believe
A junior archivist at the Hearth-Core Citadel has discovered that the oldest surviving copy of the Hearth-Core Concordat’s oath differs from the public version.
Warden-Elder Isaura Vent-Keeper asks the party to find the sealed original, recover its missing clause, and help decide whether it should be shared with the Concordat, entrusted to her, or kept sealed. The route leads from a tense Council Moot through a miscalibrated gauge gallery and into an old vault whose repair has gone unsigned for generations. An Absolute raid threatens the record before the party can read it.
Background
Spring, 225 HC.
Within the Hearth-Core Citadel, heat is measured, negotiated, and guarded as carefully as any boundary. The Concordat’s public oath promises to keep heat where it is needed. A junior archivist has uncovered an older copy bearing an absent second clause. Warden-Elder Isaura Vent-Keeper wants the party to recover and read it before the Council Moot decides what the Basin may know. The clause is the first of four Cinders that can eventually form the Siphon-Breaker Greatsword. Its unfinished final sentence remains unfinished.
The stakes
The party’s decision affects who can interpret the Concordat’s oldest instruction and whether the Citadel’s leaders confront its implications together or in fragments.
The vault may lose its record, the Absolute may seize the first opportunity to reach it, and every delay risks closing the Gate-Hall before the party can act. No choice resolves the clause’s meaning or dictates what the Basin should do.
Encounters
1The Vault’s Broken Note
Combat
A 60-by-40-foot stone vault with a door at one end and a cracked entry wall at the other. Sealed gauge cabinets provide half cover; the lectern holding the oath stands near the center. Use a 5-foot grid if desired. The cabinets and lectern make the room hazardous to area effects and reward careful positioning.
Foes
Bell-Raiser, Gargantuan elemental of pressure and ringing metal, CR 18
2 Hearth-Quenchers, CR 12 each
ComplicationOn initiative count 20 each round, sealed gauge cabinets within 20 feet vent pressure. Each creature in range makes a DC 20 Constitution saving throw, taking 6d6 thunder damage on a failure or half on a success, and is deafened until the end of its next turn. A cabinet has AC 15 and 20 hit points; reducing it to 0 hit points stops its vent. A creature can use its action to quiet one cabinet with a DC 20 Intelligence (Arcana) or Dexterity check using Smith’s Tools. If an area effect damages the lectern, the oath burns. The party has three rounds before the Pressure Surge reaches the lectern; a creature can use its action to retrieve the oath with a DC 20 Dexterity (Sleight of Hand) check, succeeding automatically if the lectern has not been hit.
ScalingFor three characters, remove one Hearth-Quencher. For five characters, add one Vent-Glass Colossus Vault Sentinel, listed at 8,400 XP in the supplied encounter design. The supplied four-character encounter totals 48,500 XP and is High for four level-17 characters. If The Gate Closes fills, begin with the Quenchers already inside and the vault seal cracked. Use the sourcebook’s Bell-Raiser traits, including Legendary Resistance and legendary actions. The Quenchers flee if the Bell-Raiser falls.
Cast
4Warden-Elder Isaura Vent-Keeper
QuestgiverQuestgiver and ally; Ursoid priest, gentle in manner and direct about the stakes.
WantsWants the party to recover the oath and make a deliberate choice about who hears it, before political urgency turns discovery into a contest for control.
“I was not told what is in the clause. I was told only that it is not a weapon.”
High Archon Ottar Frost-Bane
Political obstacle; Magma-Forged Jotun-Kin council member who can be persuaded, but resists public disclosure.
WantsWants to keep the Concordat coalition intact and fears the clause will provoke rival oaths and panic.
“If every hold has a copy by morning, every hold will have a plan by evening.”
Brannoch Slate-Hand
Witness and reluctant council voter; Ursoid noble, frightened rather than malicious.
WantsWants to conceal his part in adjusting the Quiet Gauge, while fearing that the hidden record implicates more than him.
“I moved the gauge three degrees. I did not know what it was hiding. I only knew someone would ask me why.”
Salk Vorda
Civic auditor and potential ally; his ink-stained paws and brass gauge make him easy to recognize.
WantsWants the clause published and the Citadel’s records made accountable, but fears retaliation for exposing them.
“The figures are in the ledger, and the ledger is in the room. I will not pretend either one is harmless.”
How it ends
Rewards
Items
Mantle-Forged Abyss-Plate, legendary armor; one character can attune to it. Use the sourcebook’s item entry.
Oath-Cinder, the first shard for the Siphon-Breaker Greatsword. It warms when the Ember’s spark settles into it; use the sourcebook’s Appendix B.
On a win
The party recovers the other clause and survives the raid.
The text says that when the gauges fall by a third, a keeper may sit in the seat and keep the beat; if the keeper fails, the line may be cut at the heart, with those who cut it bearing the cold. If neither is done, the count continues and whatever answers will hear its end. The final sentence stops at “And if the count is answered, then let”. The party’s choice determines who receives the text and shapes Concordat Standing and Drift, but no option is presented as the uniquely correct one. On recovery, the Ember sheds a Cinder that settles into the dull metal shard presented as the first fragment of the Siphon-Breaker Greatsword.
What it leaves open
If it fails
- The Council Moot does not grant the party its desired authorization.
- If the party fails council success checks, each failure advances The Gate Closes. Two failures against the same member lose that member’s vote for this Moot. The faction clock has six segments; when filled, the Absolute reaches the vault first, the fight begins with the Quenchers inside and the seal cracked, and the Count gains an extra mark.
- The party fails to secure a readable copy of the clause.
- If the vault is reached after the Absolute, the oath is in immediate danger and the group must contend with the altered starting conditions. If the lectern is struck by an area effect, the oath burns; if it is not retrieved before the third round’s Surge reaches it, it may be lost.
- The Concordat receives no immediate public resolution, and future access to the clause is harder.
- If the party seals the vault without recovering or preserving the clause, it must be found again in Act V. This costs a day and Isaura’s goodwill. If the party skips the vault, the Absolute raids it and the later search is substantial.
- The party leaves the decision unresolved, with political suspicion and competing interpretations growing.
- A failure to reach agreement does not force publication or destruction. Isaura can keep the recovered text close, though doing so may cost a Favor later. Council factions may act on rumor rather than verified text.
Complications (d6)
- 1A council messenger announces that the Moot has been moved forward by an hour. The party must finish its current scene promptly or take one tick on The Gate Closes.
- 2A dock bell repeats a route-like pattern from the arrival scene. Anyone who investigates hears the pattern subtly change as they approach the Old Gauge Run.
- 3A craft-warden refuses to discuss the old repair while other workers are present. The party can gain a private audience by offering protection or showing a credible record.
- 4A sealed gauge cabinet gives a brief, cold shudder. The nearest metal fittings ring softly, alerting a nearby Absolute agent that the vault trail is active.
- 5A council member’s aide sees the party enter the Old Gauge Run without an escort. Tick The Gate Closes once unless the party persuades the aide to keep quiet.
- 6A sudden vent discharge chills a corridor and fogs its glass. A character must guide an anxious group of workers to a warm shelter, delaying the party or earning a Favor with the Concordat.
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