Plot summary
Crane discovers the Freemasons in Sleepy Hollow have been beheaded by the Horseman, and realizes that the creature is seeking its own head. Irving recovers the head from the lab (where it has stymied attempts to categorize it) before the Horseman comes for it, barely escaping with his life. Crane and Mills cannot destroy the head by normal means, so they use it to lure and trap the Horseman within a magical chamber built by Thomas Jefferson.
Credits
Adapted from Wikipedia contributors, Sleepy Hollow season 1. HTML formatting and reference markers removed.