Dr. Emilia Priestly (Elizabeth Henstridge), a London Police psychiatrist, takes a break from her stressful job at the Mystery Island resort, which hosts an immersive murder-mystery-themed retreat for its investors. When John Murtaugh, the resort's reclusive founder, is murdered, Dr. Priestly teams up with local detective Jason Trent (Charlie Weber) to help solve the case and uncover the web of romance, revenge, and betrayal behind the resort and its guests.