Centuries ago, a beholder named Yeryl fled from the place of his birth and wandered the countryside in search for a place to call home. After many sleepless nights spent carving out a safe nook for himself in the wilderness, he at last slipped into slumber. In his dreams, he found an ideal place for his lair: long-abandoned ruins hidden amidst a dull and barren valley. Yeryl spent years transforming the place to suit his paranoid designs. Visitors were rare enough, and the few that made it to Yeryl’s lair were quickly destroyed or forced into the beholder’s service, building the lair ever deeper and more magnificent. As time went on, Yeryl finally completed his task. Safe at last, but with nothing to occupy his mind, Yeryl was struck by melancholy; was this lonely and empty life truly what he had chosen for himself? On that day, Yeryl made a decision: next time an adventurer came to his lair, he would welcome them in. With this resolution in mind, Yeryl began to dismantle his traps and replace them with ones he considered to be more fun. Unfortunately, for all his good intents, Yeryl has not yet realised that killing people is a bad way of getting them to like him. Yeryl's Super Happy Fun Murder Dungeon is a highly obnoxious and mildly ridiculous collection of traps, combat and puzzles designed to test your players' wits and patience. It is optimised for a group of four to five 3rd level players, but the text also contains a guide for level adjustments for different sized groups.

This adventure is the ninth part of the Shackled City Adventure Path that began with "Life's Bazaar" (Dungeon #97) Wherein a group of diverse and talented allies learns the folly of not working together against a common foe.