Last Orders at the Yawning Portal

From the introduction: Durnan has closed the Yawning Portal and mysteriously disappeared back down the well into Undermountain. His old adventuring companion Mirt has hung up his tankard and set off to find him, but he can’t do it alone. Champions gather from afar to answer his call and rescue one of the city’s most iconic heroes. Will you join them? A Three-Hour D&D Epics adventure for Tier 1-4 characters. Optimized for APL 3, 8, 13, and 18.