When Lord Montbarry dies suddenly in his Venice palace, and his courier goes missing, suspicion is instantly thrown on his new wife, the beautiful Countess Narona, who has collected his life insurance and fled to America. Montbarry's former fiance Agnes, still harbouring feelings for him, and Henry Westwick, Montbarry's younger brother, decide to investigate this tragedy and head for the palace, now a hotel. Not long after their arrival they experience strange and unsettling occurrences, and the circumstances of Montbarry's death begin to unravel...