When Shane and Aimee Lancaster move to Sleepy Hollow, New York, a string of strange occurrences begins. Animals start behaving strangely, a ghost dog starts running around at night, and the legendary Headless Horseman rides, searching for his head.

Aimee, Shane, and their new friend Stasia decide to investigate, since the police don't believe the teens' theory that the Headless Horseman's murders were done by a real Headless Horseman.

While investigating, Aimee and Stasia discover that Aimee and her brother are descendants of Ichabod Crane, and that Washington Irving's story was more of a (somewhat) toned-down version of what really happened in Sleepy Hollow.

Aimee and Shane decide that they are the only ones who can stop the Headless Horseman from terrorizing the town again.