One night, New York FBI agent Aiden Mahoney receives a visitor in a dream-an old friend named Richard Highsmith. The very next day he's sent to Sleepy Hollow because Richard's gone missing there. Maureen "Mo" Deauville now lives in the historic town and works with her dog, Rollo, to search for missing people. She's actually the one to find Richard . . . or more precisely his head, stuck on a statue of the legendary Headless Horseman. Mo and Aiden, a new member of the Krewe of Hunters, the FBI's unit of paranormal investigators, explore both past and present events to figure out who betrayed Richard, who killed him and now wants to kill them, too. As they work together, they discover that they share an unusual trait-the ability to communicate with the dead.