A double murder, disguised as a boating accident, claims the lives of two cousins, leaving an immense fortune hanging in the balance. Haunted by a past tragedy, Detective Sean Lloyd travels from London to Halifax Manor to investigate. While there, Lloyd is drawn into a dark web of household secrets, implicating the remaining four cousins. When Lloyd becomes attached to one of the cousins, Evie Osborne, he is forced to confront his demons. As Lloyd probes the girl's mind for clues, he summons up more than he bargains for. As he races against the clock to solve the crime before the murderer strikes again, every revelation brings him closer to a shocking and unforgettable conclusion.