“A glass fortress has been falling for three hundred years. The party is the first to reach it before it lands.”
The party is contracted by the Velton Cartographers' Guild to charter Captain Venera Tass's sky vessel *The Quiet Compass* on a final approach to the citadel. The Guild has tracked the island's descent for three centuries; recent storms have accelerated its fall by a factor of ten. Whatever records the cartographer-priests left in the Glass Archive must be salvaged before the citadel strikes the eastern Reaches — and whatever the planar device at the citadel's heart was built to hold in place must be held in place a little longer. The party is being paid to bring back the cartographers' last survey and, if possible, to confer with the Glass Quill itself.
Themes — The cost of perfect knowledge. What is salvaged is not always what is saved. The fall of a place does not have to mean the failure of what was made there.
The party boards *The Quiet Compass*, ascends through the storm line, lands on the citadel's outer stair, and makes first contact with the salvagers already camped there.
*The Quiet Compass* is a three-mast sky vessel with a battery of storm-warded sails and a glass-hulled observation deck. The climb from the eastern Reaches to the storm line takes four hours and requires the pilot (Captain Venera Tass or her first mate) to make three DC 14 Piloting checks — failure means the vessel is pushed off course, costing an hour and 20 gp worth of storm-ward fuel. The storm line is a 200-foot-thick bank of layered cumulonimbus and lightning; the citadel floats above it, visible only as a silhouette lit from within. The outer stair is a 40-foot-wide spiral of fused glass and stone running down the island's eastern face. The party establishes forward camp on a flat terrace two levels below the storm-warded gate. They encounter the first salvagers — three freelancers from the lower city of Velton — already camped and prospecting the lower galleries.
The party ascends to the upper galleries, meets the Cartographer-Priestess who has remained in the citadel, and contends with Captain Venera Tass's rival claim in the glass archive.
The upper galleries are a continuous ring of vaulted rooms running the island's circumference. Most have collapsed into open sky; one — the glass archive — is intact, sealed by a ward of living light. Inside, the archive contains three centuries of unbroken survey records from the order of planar cartographers. Two of the order's defenders remain: Sister Halen Vra, a Cartographer-Priestess who has refused to leave, and Captain Venera Tass, who is here not for the surveys but for the calculators — instruments she intends to sell to the Velton Cartographers' Guild and use as leverage in a contract dispute. Tass is not hostile by default. She is here for the same things the party is here for, and she has already been here longer. The session alternates between a combat encounter with Halen's glass sentries in the eastern gallery and a contested social/roleplay beat with Tass in the archive.
The party descends to the Sanctum, meets the Glass Quill itself, learns the truth of the citadel's fall, and makes a choice about what to do with the citadel's final survey.
The Glass Quill is the citadel's central planar device — not a creature, but an instrument, an intelligent artifact built by the order of cartographers to anchor island-spaces above the storm line. It has not been maintained in three centuries; its current custodian is Sister Halen Vra, and her refusal to leave is a refusal to stop maintaining it. The Sanctum is a vertical chamber — 30 feet across, 80 feet tall — that was once a working library. The Quill floats at its center, six feet of fused crystal and windset glass, surrounded by the carved records of the order's final survey. The Quill speaks to those who reach it; it is not hostile, but it has been falling for three centuries and the strain is showing. The party must decide whether to anchor the citadel for another three hundred years (which requires the surveys and a willing anchor), release it to fall (which requires the calculators and a willing surveyor), or take the surveys and let the order's work speak for itself (which is the Guild's contracted outcome but is not what the surveys were written to do).
