First-year history professor Mitchell Lambert has written a biography of Maria Boudreau, a famous young heiress who died more than eighty years ago. The book has sparked renewed interest in Maria, and now people are seeing her ghost on Sumner Island off the coast of Maine where she was brutally murdered in 1924. As interest in the ghost story grows, a séance is planned at the island's grand hotel to be conducted by world-renowned ghost hunter Horace Leeds and his medium Phyllis Church. Mitch, who has been hopelessly infatuated with Maria since he first began researching her life, manages to get himself invited to the ghost hunt. As the next twenty-four hours progresses, Mitch is delighted to discover that Maria's ghost is drawn to him. Eventually, he is forced to recognize that he is somehow hardwired into Maria's past. All of this leads Mitch to realize that he was purposely lured to the island, not only to resolve some old issues and answer some lingering questions, but to fulfill an unknown mission that only Maria knows about. But that mission may be thwarted by the ghost of her murderer, who has some unfinished business of his own.