A horrible crime has been committed on the grounds of Warwick Manor and it's up to the psychic investigators to get to the bottom of it. In Mysterium, one player takes on the role of the ghost and, over the course of a week, tries to lead the investigators to their culprit. Each night the team will be met with visions, but what is the ghost trying to tell you? Can the psychics determine the weapon, location, and killer - or will a violent criminal pull off the perfect murder?