Lieutenant Castiel Milton of the Sleepy Hollow Sheriff’s Department has been hiding a secret from his youth - the truth of what he and his sister, Anna, saw one afternoon when they got lost in the woods on the way home from school. Anna went mad from the strain of battling her many demons, while Castiel buried it deep and tried to move on. The bright young Lieutenant is all set to go to Quantaco and leave his dark past behind him when the grizzly murder of Sheriff Chuck Shurley leaves him reeling. Things all get much more complicated when he meets Dean Winchester, a strange man who claims to remember nothing since the last battle he fought in the Revolutionary War, 250 years prior. The two are inexplicably linked, and together they must discover the truth about the mystery of the horseman stalking Sleepy Hollow, as well as about each other.