Razored Labyrinth is a long-form maritime-to-abyssal campaign set around the western waters of the Castrovin Sea in Casmaron. It begins as a local investigation beneath the Bridge of Kridorfrost and expands into pirate intrigue, locathah diplomacy, undersea map lore, ruined Ninshabur, recovered submersibles, and finally a dry Darklands assault against a catastrophic excavation project tied to the Pit of Gormuz and the legacy of Rovagug’s Spawn.

Core Campaign Shape

GM Sequential Plot

Act I — The Sinkhole Beneath Kridorfrost

The campaign opens in Kridorfrost Village, built around the ancient Bridge of Kridorfrost over the Noyrus River. A large sinkhole opens beneath one of the bridge’s lower supports during maintenance, with one worker sucked in and old flooded tunnels exposed. The party is hired for rescue, stabilization, and investigation.

The visible truth is a cave-in. The deeper truth is that renewed excavation far below destabilized a partially collapsed Darklands connector spur. The party finds old stonework, flooded cyclopean chambers, strange tool marks, obsidian fragments, and hints that smugglers had already discovered parts of the ruin before the accident.

Act II — Kridorn and the Obsidian Trail

The party follows trade markings and smuggling clues south to Kridorn, the river-mouth port where piracy, salvage, foreign trade, and relic speculation all overlap. Here they learn of increased pirate activity around Black Glass Peak, a volcanic formation streaked with pure obsidian and claimed by territorial locathahs.

The pirates are not ordinary treasure seekers. They are disciplined, equipped with diving gear, using reinforced ships, and harvesting obsidian in bulk. Their work is organized by a Darklands-facing intermediary who pays local pirates, surface laborers, corrupt brokers, and low-level subterranean agents without revealing the final purpose.

Act III — Citadel Allatro and Black Glass Peak

The party books passage to Citadel Allatro, a solitary sea-stack trading post used by locathahs. There they meet Talaris Wavebreaker, a locathah Wave Rider cavalier, and Shulassa Deepcurrent, a locathah Deep Shaman of the Waves spirit. These NPCs become maritime allies, not permanent land companions.

Talaris has witnessed increasingly organized pirate raids near Black Glass Peak. Shulassa knows that ancient locathah and merrow carvings beneath eighteen sea stacks may form an underwater route through the Razored Labyrinth to a hidden sea-floor entrance. Clues from Black Glass Peak and pirate camps point toward lost Ninshabur as the best place to recover missing map fragments.

Deep Lore and Major Revelations

Act IV — Ninshabur and the Lost Map

The party works with a Keleshite trader-patron to sail toward Ninshabur. This leg gives the campaign broad Pathfinder lore weight: Keleshite trade interests, the ruined memory of Ninshabur, Rovagug’s Spawn, and the ancient fear that some subterranean works beneath Casmaron should never be completed.

In drowned archives, collapsed vaults, and surviving inscriptions, the party recovers enough of the underwater map to follow the sea-stack route. They also discover historical references to an ancient connector tunnel beneath the Castrovin basin. In Ninshabur’s final age, scholars or engineers learned that something below was being excavated toward abyssal regions associated with the Pit of Gormuz. The project was abandoned or interrupted during cataclysmic events tied to the Spawn of Rovagug.

Act V — Vladmirr and the Apparatuses

With the underwater map in hand, the party goes to Vladmirr, a sinking delta-port and salvage hub. Here they must locate, recover, repair, and test two Apparatuses of the Octopus. Assume two party members can function without subs through magic or other means, while four require the two-person vessels.

Act VI — Beneath the Razored Labyrinth

The recovered underwater map guides the expedition through sea-stack routes, submerged ruins, volcanic ridges, drowned transit chambers, and abyssal currents beneath the central Castrovin Sea. The Apparatuses are pressure shelters, cargo carriers, light sources, and survival platforms.

Act VII — The Drying Descent

The underwater passage eventually slopes into geothermal chambers where the sea drains away through vast fissures. Floodgates, pressure doors, and cyclopean seals mark the end of the maritime campaign. Talaris and Shulassa stop here, promising to guard the route, delay reinforcements, and preserve an escape path if the party returns.

Final Acts and Antagonist Structure

In the dry Darklands, the party finally uncovers the full plot. A major Darklands antagonist has organized local surface pirates, Kridorn brokers, low-level Darklands labor, corrupted miners, and abyssal cult specialists into a vast excavation network. The target is the ancient incomplete connector tunnel beneath the Castrovin basin.

Spawn-Like Defenders

Late-game defenders should feel increasingly artificial and unfinished: obsidian-armored tunnel beasts, pressure-warped giants, larval Spawn fragments, abyssal excavation horrors, corrupted Darklands fauna, volcanic siege organisms, and malformed guardians bred to defend the spawning chambers.

Final Objective

The party must sabotage the spawning chambers, disrupt the obsidian containment lattice, defeat or bypass Spawn-like guardians, and collapse the connector tunnel before it links the Castrovin basin to abyssal territories associated with the Pit of Gormuz.