Dead Water CR 12
When this haunt is triggered, torrents of gray water littered with bones, dead flesh, and worms suddenly gush out of the catacombs’ alcoves, creating an inescapable wave of water that quickly floods the catacombs. All creatures in the catacombs are affected by a weird spell (save DC 23).
Those affected by the haunt believe they are drowning in the churning waters, which appear to recede as quickly as they filled the tunnels.
Pathfinder Adventure Path #48: Shadows of Gallowspire. © 2011, Paizo Publishing, LLC; Author: Brandon Hodge.