Remember the good old days, when adventures were underground, NPCs were there to be killed, and the finale of every dungeon was the dragon on the 20th level? Those days are back. Dungeon Crawl Classics adventures don't waste your time with long-winded speeches, weird campaign settings, or NPCs who aren't meant to be killed. Each adventure is 100% good, solid dungeon crawl, with the monsters you know, the traps you remember, and the secret doors you know are there somewhere. A deadly blue mist fills the streets of Fair Haven, slaying many of the small town's inhabitants and driving the rest insane. The mist's source is hidden in the town's dark sewers. To save Fair Haven, the heroes must explore the catacombs beneath the town, solve an ancient riddle, and defeat a sahuagin menace. But their journey does not end there ‐ for an unspeakable devil from a forgotten plane of existence lurks within the mists... This adventure can be played as a sequel to Dungeon Crawl Classics #7: Secret of Smuggler's Cove, or can be played on its own.