Beneath the Razored Labyrinth · Adventure Overview (Spoilers)

Adventure Summary

The Castrovin Sea is vast, storm‑scoured, and treacherous. Most sailors hug the coastline, avoiding the deeper waters and the jagged volcanic maze known as the Razored Labyrinth. Inland, the ancient Bridge of Kridorfrost stands as the only crossing of the Noyrus River for a hundred miles—a cyclopean relic of the fallen Koloran empire. The bridge‑town of Kridorfrost lives by tolls, timber, and river‑trade, but when a sinkhole opens beneath the bridge's lower supports, workers vanish into flooded tunnels, and the town's fragile prosperity begins to crumble.

The heroes begin as locals and outsiders caught in the first wave of the crisis. Their earliest problems are practical: missing workers, a collapsing bridge, strange obsidian fragments in the rubble, and rumours of organised smugglers using the tunnels. Soon the investigation points south to Kridorn, where pirate‑brokers and salvage crews know more than they admit, and to the sea‑stack trading post of Citadel Allatro. What appears to be a local accident becomes something larger: a Darklands‑connected conspiracy using the Razored Labyrinth as a surface breach.

By mid‑campaign, the party leaves the river behind and ventures across the Castrovin Sea—through sea‑stack mazes, submerged ruins, and lost Ninshabur. They uncover evidence of an older power beneath the Castrovin basin, one tied to the ancient cyclopean empire and perhaps even to the Spawn of Rovagug. Locathahs, merrows, Keleshite traders, and salvage engineers all hold part of the truth.

The final arc descends beneath the Razored Labyrinth into dry volcanic caverns and Darklands tunnels. The heroes must decide whether to seal the breach, sabotage the spawning chambers, or expose the conspiracy before the abyssal forces gain a permanent foothold. Victory means saving Kridorfrost and the southern Castrovin coast; failure means the sea lanes collapse, the ancient horror awakens, and the Darklands gain a road to the surface.

Major Story Arcs

Adventure Structure Overview

The campaign is built around a sequential expedition model: each arc builds on the previous, and clues from one region lead to the next. The overall threat escalates whether the party pursues it or not.

Seven PCs — Suggested Character Hooks

This campaign supports a party of up to seven. The following hooks tie each character to the central conflict while offering personal stakes.

GM Tools & Resources

This section provides quick‑reference tools for running the campaign: random encounter tables, faction summaries, and suggested DCs by level.

Random Encounters by Region

Faction Quick Reference

Suggested DCs by Level

Based on Pathfinder 2E DC‑by‑level guidelines. Adjust for party composition and desired difficulty.