Adventure Summary: A one-session heist and rescue for four to five 5th-level characters. A celebrated cartographer is being sold with the route hidden in his memory, so the party must enter a floating auction, free him, and escape before the pavilion leaves the city airspace.
Brass Comet Saga: Part 1 of 4. This adventure stands alone. The saga continues with The Clockwork Embassy Job.
Overview
The Skyglass Exchange has put cartographer Iven Rook inside a brass display cage and advertised an exclusive map to a comet trail. Courier Nyra Vale offers the party 700 gp to rescue Iven and destroy the bidder ledger before a private army buys both.
Track Alarm from zero to four. Add one after a failed group infiltration check, obvious violence, or ten minutes in a restricted area. At Alarm 2, doors require a DC 14 tool or Arcana check. At Alarm 4, the pavilion undocks and the Aether Crane finale begins.
Background
Iven mapped a bright object called the Brass Comet, then learned the route can redirect commercial sky lanes. Auctioneer Caldus Pell kidnapped him for Magnate Orin Veyr, who intends to make every airship pay for access. Iven hid the final coordinate in a harmless paper bird carried by Nyra.
Standalone hook: Nyra supplies invitations, formal clothing, a compact glider, and an exact extraction time. Rescuing Iven and erasing the ledger resolves the job completely, whether or not the party follows the comet clue afterward.
Characters
- Nyra Vale: A quick-witted courier who plans the approach and flies the escape airship.
- Iven Rook: A patient cartographer who memorized the auction’s security rotations.
- Caldus Pell: The smiling auctioneer, willing to bargain until his ledger is threatened.
- Brass Sentinel: A tireless construct programmed to protect the cage and paying bidders.
Setting
The labeled map connects the Docking Spire, Guest Gallery, Ledger Room, Auction Floor, Aether Crane, and Escape Mooring. Glass floors are sturdy but transparent. A creature shoved against a railing may make a DC 13 Dexterity save to catch it.
Guests wear numbered masks. A character with a mask has advantage on the first Deception check made in a public room. Restricted doors use paired blue and brass tumblers, DC 14 with thieves’ tools, Arcana, or a stolen staff seal.
Plot Outline
The party acquires masks at the Docking Spire, scouts the Guest Gallery, enters the Ledger Room, frees Iven during the auction, defeats or deceives Pell’s sentinel at the Aether Crane, and leaves by Nyra’s airship with the prisoner and ledger problem resolved.
1. Invitations at Altitude
Two ushers compare masks to invitations. Three DC 13 Deception, Performance, or Sleight of Hand successes admit the group. A failure raises Alarm but Nyra creates a cargo spill, allowing entry through the Docking Spire maintenance hatch.
2. The Guest Gallery
Characters can question bidders, study the crane controls, or steal Pell’s seal. Each useful lead requires DC 13 Insight, Investigation, or Persuasion. Two successes reveal Iven’s cage lowers through the floor and the ledger room opens during the third lot.
3. Burn the Ledger
The ledger is inside a glass cylinder with three rotating account rings. Three DC 14 Arcana, Investigation, or thieves’ tools successes open it before two failures. Destroying the ledger is automatic once opened. Copying it first exposes Pell’s clients but adds Alarm.
4. The Auction Floor
Iven’s cage has AC 16, 30 hit points, and a DC 15 lock. The party may bid with forged credit, cut power beneath the floor, or create a distraction. Pell surrenders the key if confronted with the copied ledger and a DC 15 Intimidation or Persuasion check.
5. Aether Crane Escape
The Brass Sentinel blocks the crane while the pavilion begins moving. The party wins by defeating it, earning three DC 15 Athletics, Arcana, or vehicle successes to lower Iven, or presenting Pell’s seal and passing a DC 16 Deception check. At initiative 20, the rotating floor moves each unsecured creature 10 feet toward a railing.
6. Clear Skies
Nyra catches the crane platform at the Escape Mooring. Iven is safe, Pell’s buyers lose their claims, and Nyra pays in full. The paper bird unfolds into a coordinate for the Clockwork Embassy, a future lead that does not diminish the completed rescue.
NPCs and Monsters
| NPC or Monster | Statistics | Key Abilities and Table Notes |
|---|---|---|
| Nyra Vale | Medium humanoid; AC 14, HP 38, speed 30 ft. | Rapier +6, 1d8 + 3 piercing. Airship Pilot grants advantage on one escape or docking check. She protects passengers before cargo. |
| Iven Rook | Medium humanoid; AC 11, HP 24, speed 30 ft. | Investigation +7, cartographer’s tools +8. Route Memory grants one automatic navigation clue. He hides and assists rather than fighting. |
| Caldus Pell | Medium humanoid; AC 15, HP 52, speed 30 ft. | Cane blade +5, 1d6 + 3 piercing. Once per round he can redirect a sentinel reaction. He bargains when the ledger is exposed. |
| Brass Sentinel | Large construct; AC 17, HP 85, speed 30 ft. | Two brass fists +7, 2d8 + 4 bludgeoning. Anchor Cable restrains, escape DC 15. Pell’s seal and a DC 16 check can shut it down. |
Rewards
- 700 gp from Nyra’s rescue fund and a permanent favor from Iven’s cartographers’ guild.
- Skyglass Skeleton Key: This uncommon key opens one ordinary lock automatically per dawn and can make a transparent platform opaque for ten minutes.
Scaling the Adventure
For 4th level, reduce the Sentinel to 68 hit points and Alarm begins at zero. For 6th level, add two auction guards and raise the Seal Protocol DC to 17. For a two-hour session, begin in the Guest Gallery with Pell’s seal already identified. For groups avoiding heights, the pavilion floats only 30 feet above a deep safety net and every fall ends on that net.
Skyglass Auction-Themed Table Gear
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- Fantasy airship miniature. Marks Nyra’s extraction point and makes the moving crane rescue easy to stage.
- Transparent blue acrylic tiles. Build the auction’s glass floor and reveal restricted rooms beneath it.
- Numbered masquerade masks. Give the infiltration a tactile identity puzzle and track compromised disguises.