In 1781, Ichabod Crane, a soldier in the Colonial Army, set on a secret mission by General George Washington to kill the man with the branded hand, later to become the Headless Horseman after Ichabod cuts off his head. Sadly, Ichabod dies while performing this task. More than 200 years later, in the present-day Sleepy Hallow, Ichabod rises from his grave, after the Headless Horseman known as Death and one of the Four Horsemen of the Apocalypse, is coincidently summoned back from his grave. Both brought forth from an unknown source. The resurrection of the one causes the other to also come back to life as a result of their blood mixing shortly after Crane decapitated the Headless Horseman on the field of battle.
Lt. Abbie Mills, of Sleepy Hollow, is caught up in the investigation of the Headless Horseman after he beheads Sheriff August Corbin, Mills' mentor and friend. As Lt Mills' investigation reveals the presence of the Supernatural world involving two occult groups - one for good, the other evil - in Sleepy Hollow, both of which are concerned with the Four Horsemen and the associated apocalypse.
With Ichabod's first-hand knowledge of this country’s history and secret societies and Abbie’s superior profiling and modern threat assessment skills, the reason why she was accepted in to the FBI, they team up to work the case of the Horseman’s killing spree. Eventually, she stays behind in Sleepy Hallow under Ichabod’s protest, as to not go off to become a federal agent. After witnessing unnatural forces, they form an unstoppable team once realizing their lives are preordained. As they are the two witnesses, the only ones who can protect the world from the forces of evil.
This is a modern day twist on Washington Irving's classic in which Ichabod Crane and Lieutenant Abbie Mills fight vigorously to save the town of Sleepy Hollow from Hell on earth.