From the Introduction: This delve is an event‐based adventure that takes place over the course of a night, entirely within the confines of a single mansion. Unlike a traditional delve of characters exploring a dungeon, this adventure charges the players with piecing together clues to a crime, while at the same time fending off attacks and protecting the innocent against the fantastic and dangerous beasts of the Feywild from savaging the guests at a royal birthday party and masked ball. The actions and decisions of the PCs determine the locations of several of the encounters, with the DM determining when the encounters happen. The delve has no setting‐specific material, and can fit into almost any ongoing campaign. This delve typical takes 3 hours to complete.