Looking Glass Deep

A free short adventure for four 4th-level characters by Mike Mearls
Looking Glass Deep is a flexible, site-based scenario that presents you with the details of the ruined abode of the wizard Urlen Sparlek -- and the gang of outlaws that now occupies the place. This 10-page adventure by Mike Mearls is designed for 4th-level characters.
Unlike some site-based scenarios, Looking Glass Deep features a dungeon full of monsters that take proactive steps to defeat the player characters (PCs). Tzarrik the hobgoblin sorcerer is an intelligent tactician with the ability to spy on the party almost at will when the group is within the Deep. His ragged gang of followers work together as a team under his command to repel attackers.
Throughout the course of the adventure, the characters have the opportunity to locate an artifact called book the key of the way , discover the mysteries of the throne of the Deep -- and perhaps, in the end, even gain themselves a new headquarters.