A horrible crime was committed on the grounds of Warwick Manor, thirty years ago. Now, the mansion is haunted by the ghost of the murdered servant, and it's up to a group of psychic investigators to get to the bottom of the mystery. Mysterium is a cooperative game of deduction and teamwork for two to seven players. Over the course of the game, one player takes on the role of the ghost and over the course of a few scant hours, tries to lead the psychics to the correct culprit. Every member of the team will receive numerous visions, but what is the ghost trying to tell you exactly? Can the psychics determine the weapon, location and killer, or will a violent criminal pull off the perfect murder?