Adventure Summary: A one-session mystery and political thriller for four to five 6th-level characters. During a dwarven coronation feast, an attempted murder exposes a conspiracy linking the Hammer of Grondar, the Frostline disturbances, and the Stormglass Vault. The party must gather evidence, identify the traitor, and stop a ritual in the Hall of Echoes. It stands alone or concludes the four-part Stormglass Saga.
Overview
Thrain Ironfist has invited rival clans to witness a new accord and the ceremonial return of the Hammer of Grondar. Before the oath can be sworn, Elder Borin Slateward collapses after drinking from a stormglass goblet. The goblet shatters, a hidden lightning rune flares beneath the council table, and the great doors seal.
Borin survives if treated quickly, but the failed assassination is only a diversion. Chancellor Dagna Flintmantle plans to steal the Hammer and combine it with the Stormglass Key in the Hall of Echoes. The resulting resonance will compel the assembled clan delegates to accept her as High Chancellor, or kill everyone in the hall if the ancient mechanism fails.
Background
Dagna believes the scattered mountain clans can survive only under a single ruler. Years ago, she secretly paid Gorgak to steal the Hammer of Grondar, expecting the theft to discredit Thrain. Gorgak kept the artifact and tried to claim its power for himself. Dagna then funded Veyra Soot’s search for the Stormglass Vault, presenting the expedition as ordinary salvage.
Optional sequel: If the party completed The Stormglass Vault, Bruni Coalvein recognizes the goblet as a missing piece from Kharum-Zek, while the Stormglass Key reacts to the hidden rune. Veyra, if she survived or surrendered, can send a warning that her anonymous patron used a black mountain seal. Characters who recovered the vault plans can find Dagna’s payment cipher in the margins without making a check.
For a standalone adventure, the characters are neutral troubleshooters hired to protect the summit. Give them the same starting evidence: the poison was carried in a stolen stormglass vessel, a gray-cloaked intruder was seen near the Archives, and only five officials knew the coronation route.
Characters
- Thrain Ironfist: Host of the summit and obvious political beneficiary. He is proud, angry, and genuinely innocent.
- Chancellor Dagna Flintmantle: Respected elder, patient conspirator, and architect of the crisis. She never lies when a technically true answer will suffice.
- Elder Borin Slateward: Intended victim and critic of centralized rule. Blunt but observant; he remembers smelling forge oil before drinking.
- Bruni Coalvein: Archivist and returning ally. She knows the halls, vault records, and Dagna’s habit of using obsolete ciphers.
- Captain Rurik Emberlane: Head of security and a convincing suspect. His missing cloak and master key were stolen while he slept.
Setting
The Ironfist halls are a fortified complex of feast chambers, archives, shrines, guest quarters, and old ceremonial passages. The Great Hall remains sealed during the investigation, but side doors can be opened with Rurik’s keys or DC 14 thieves’ tools checks. Bronze speaking tubes connect several rooms, allowing the conspirators to create false alibis.
Each investigation scene consumes roughly twenty minutes. After the third scene, Dagna leaves for the Hall of Echoes. After the fifth, she begins the ritual. The characters can split up, enlist trusted NPCs, or move quickly by finding the Smuggler Tunnel.
Plot Outline
The party stabilizes Borin, examines the feast, and chooses which locations to investigate. Every location contains one clue and one misleading detail. Three core clues identify Dagna; four reveal her destination; five explain how to stop the ritual safely. Accusing the wrong suspect gives Dagna time to reach the Hall of Echoes but does not end the adventure.
1. The Shattered Goblet
A character can stabilize Borin with healing magic or a DC 12 Wisdom (Medicine) check. Examining the fragments with DC 13 Intelligence (Arcana) reveals that stormglass amplified a contact poison called emberbane. The hidden table rune was traced with forge oil and points toward the Bell Stair when warmed. A server saw Captain Rurik near the table, but a DC 12 Wisdom (Insight) check reveals the witness only recognized Rurik’s gray cloak.
2. Follow the Evidence
Let the party visit locations in any order. In the Archives, Dagna’s payment cipher appears in a ledger beside shipments to Gorgak and Veyra. In the Forge Chapel, the same rare oil used on the table rune stains Dagna’s ceremonial glove. In the Guest Quarters, Rurik’s cloak is hidden beneath a bed, but muddy prints lead toward a speaking tube. In the Council Chamber, a wax impression of Dagna’s black mountain seal lies in the brazier. At the Bell Stair, a torn strip from Dagna’s robe is caught on a concealed door.
A DC 14 Intelligence (Investigation) check at any two linked locations reveals that one person used the speaking tubes to imitate Rurik’s voice while wearing his cloak. Bruni can decode the ledger automatically; otherwise it requires a DC 15 Intelligence check.
3. Question the Suspects
Each major NPC answers three questions before demanding evidence. Thrain admits he ordered the doors sealed. Rurik admits he fell asleep after drinking spiced ale. Bruni admits she brought the Stormglass Key to the summit. Dagna claims she “never touched Borin’s drink,” “sent no dwarf into the mountains,” and “seeks only unity.” All are literally true: an accomplice prepared the goblet, Gorgak was not a dwarf, and domination is Dagna’s idea of unity.
Presenting the ledger, glove, and seal together causes Dagna to end the interview and flee. Catching the verbal loopholes with a DC 14 Wisdom (Insight) check reveals she knows far more about Gorgak and the vault than she should.
4. The Smuggler Tunnel
The concealed stair behind the Bell Stair descends to a tunnel joining the Archives, Forge Chapel, and Hall of Echoes. Two animated armors guard its midpoint. Showing Rurik’s master key deactivates them; otherwise the party can bypass them with a DC 15 group Dexterity (Stealth) check or fight. Chalk arrows on the floor point toward the ritual chamber and confirm Dagna’s route.
5. The Hall of Echoes
Dagna stands on the resonance dais with the Hammer of Grondar and Stormglass Key. She is protected by two animated armors and a field of ancestral echoes. On initiative count 20, lightning crosses one of three rune rings. A creature standing on that ring must succeed on a DC 14 Dexterity saving throw or take 2d6 lightning damage.
The party can win by defeating Dagna, presenting three pieces of evidence to break the delegates’ faith in her, or completing three DC 15 Intelligence (Arcana), Religion, or mason’s tools checks to ground the dais. Each successfully presented clue suppresses the ancestral field for one round. Dagna uses mage statistics with 55 hit points, lightning bolt instead of fireball, and no fly spell. She surrenders if the ritual is disabled and Thrain publicly rejects her claim.
6. Judgment at Dawn
Once the ritual ends, the sealed doors open and the storm disperses through the mountain vents. If the party has at least three clues, the council accepts the accusation. With fewer clues, Dagna’s surviving allies demand a formal trial, but Borin’s testimony prevents immediate bloodshed. Thrain asks the characters whether the Hammer and Key should remain together, be separated, or be placed under a council of several clans.
NPCs and Monsters
- Chancellor Dagna Flintmantle: Mage statistics, AC 12, HP 55, lightning bolt replacing fireball, no fly spell, Persuasion +7, Deception +7.
- Thrain Ironfist: Dwarven warrior, AC 18, HP 65, Warhammer +7 (1d8+4), Leadership ability.
- Bruni Coalvein: Scout statistics, AC 13, HP 16, advantage on checks involving dwarven records or mechanisms.
- Captain Rurik Emberlane: Veteran statistics, Insight +4, Investigation +3.
- Animated Armors: Use standard animated armor statistics; they deactivate when shown Rurik’s master key.
Rewards
- 750 gp from the assembled clans for exposing the conspiracy and preserving the summit.
- Echo Seal: This wondrous medallion grants advantage on one Charisma check made when invoking dwarven law or tradition. Once per dawn, its bearer can cast zone of truth without material components.
- Clan Accord: The characters receive safe lodging, mundane repairs, and an audience with a clan elder in allied dwarven settlements.
Scaling the Adventure
For a 5th-level party, reduce Dagna to 45 hit points, remove one animated armor from the climax, and reduce rune-ring damage to 1d6. For a 7th-level party, add two helmed horrors to the tunnel, increase Dagna to 70 hit points, and let her cast counterspell once. For a shorter session, provide the ledger clue automatically and allow each investigation location to reveal its clue without a roll.
Optional Campaign Finale
If the group played all four adventures, use this ending after Dagna’s defeat. Gorgak’s theft, the shard awakening the Rimehorn, and Veyra’s vault expedition were all pieces of Dagna’s failed plan to unite the clans through fear and artifact-powered domination. The heroes now possess the relationships and evidence needed to end that cycle.
- The Hammer: Thrain offers to return the Hammer of Grondar to the clan shrine, but accepts the heroes’ counsel to seal it, destroy its stormglass channel, or entrust it to a rotating council.
- The Frostline: Orla reports that the reopened road is safe and the Rimehorn has returned to the high basin. If the guardian survived, it appears on a distant ridge during the final sunrise.
- The Vault: Bruni establishes a protected archive using the recovered plans. If Veyra survived, she can accept honest work as its first outside pathfinder, or depart after returning one final stolen key.
- The Goblins: Snik Vell receives formal sanctuary and becomes the first goblin guide recognized by the clans, proving that Gorgak’s choices need not define his people.
Thrain asks each hero to strike the repaired Hammer once against the Hall’s silent anvil. Each blow rings through the mountain without thunder or command, only a clear note answered by the bells of every clan. The Stormglass Saga ends at dawn with the passes open, the conspiracy exposed, and the future placed in mortal hands rather than magical relics.
Mystery-Themed Table Gear
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- Mystery polyhedral dice set. A thematic set for secret checks, accusations, and the final judgment.
- Random encounter, monster, treasure, and trap dice. Useful for improvising complications while the investigation clock advances.
- Mystery metal d20. A weighty option for decisive Insight checks and the climactic accusation.