Ichabod and Abbie hunt a resurrected witch who is leaving a trail of charred corpses in her wake.
Deputy Andy Brooks, who was nearly decapitated, is resuscitated and told to help a burned corpse to help her kill specific people. From his wife's cryptic warnings and Sheriff Corbin's notes, which he finds by laying bear a secret passage, Ichabod works out it's the doing of stake-burned black witch Serilda, who can only return to life if she kills the Furth bloodline before the blood-moon. Their success helps Lt. Mills believe his story about a secret war against black magic Crane was charged with by General Washington.
- Ichabod Crane races through the forest, chased by the Headless Horseman and the three other horsemen. He becomes caught in vines and is dragged down to a cave below.
He sees his wife Katrina, who tells him they're safe for the moment. "Before the four horsemen will ride, an army of evil make way for their arrival. The first dark spirit rises with the blood moon," she tells him cryptically. "She's one of us, you must stop her before she kills again," she says.
Katrina disappears and Ichabod wakes up with a start in his motel room.
At the station, Captain Irving tells Abbie Mills that the two other men who saw the Headless Horseman have recanted their stories, knowing how they sounded.
She's wondering what the explanation is for Andy's death. Surveillance footage shows him running full speed into the mirror and his head popping back, but Abbie knows that's not what happened.
She says Ichabod will back her up, but Irving points out he's not the most reliable witness and there's a psychological condition that could explain why he's so sure of who he is, even though it sounds crazy.
In his hotel room, Ichabod gets ready with the aid of Post-It explaining the shower, hair dryer and coffee machine.
Irving tells Abbie he's going to Albany and gives her some latitude to investigate. She goes to see Ichabod, who is super annoyed to be under guard at the motel.
He tells her about his vision, but she's skeptical.
In a morgue, a body comes back to life and rips its way out of a body bag. It's Andy, with his head bent backwards like a Pez Dispenser. The demon appears and pops his head back the right way, and gives him some sort of direction. Andy pulls a medallion from down his throat. The demon tells him something in whatever demon language he's speaking.
"Release who?" Andy asks.
Abbie tries to pry the story of how Ichabod met Katrina and why he didn't know she was a witch. He thinks it was for his protection. She wants to get him a cover identity.
Andy, the undead with some extra skin around his neck where it was stretched backwards, gets in a patrol car.
Abbie attends the sheriff's funeral, as Ichabod hangs back. He visits Katrina's grave, wondering what "one of us" means.
Then he realizes she was referring to a witch.
In the dead of night, Andy goes to a circle of stones and puts the medallion from the demon on it. A crusty looking dead woman appears.
He relays the demon's message: "The ashes of the pious will ordain your resurrection; take their flesh and you will reclaim yours."
Later, undead Andy pulls over a man and asks his full name, Jeremy Stephen Firth. "Jeremy, I want you to know where ever this road takes you -- and it won't be far -- it wasn't personal," Andy says. He gets in his patrol car and drives off.
The crusty dead woman leaps on Jeremy's windshield and incinerates his car with the touch of her hand.
Back at the station, Abbie is having a hard time adjusting to the idea they're after a witch. Crane thinks she hasn't had time to mourn the sheriff, whom he can tell meant a lot to her.
She tells a story about how she got into drugs after she and her sister saw the demon in the woods. She broke into a pharmacy and Sheriff Corbin caught her, but instead of taking her to jail, he took her to a diner and gave her a chance to change.
Abbie gets a call about unusual activity. It's Jeremy's burnt out car with his charred remains inside, bearing deep claw marks. There's something familiar about it to Crane.
He tells her about returning to his regiment during the war during a blood moon to find the same kind of burned out bodies. George Washington believed it was Serilda of Abadon, who had formed an alliance with the Red Coats.
They head back to the station to check the sheriff's files on the good and bad covens, but his office has been cleaned out.
While Abbie goes to find the files, a stern dude named Luke interrogates Crane, who says he's a history professor from Oxford, specializing in the American Revolutionary war. When Abbie comes back, Crane correctly guesses that Luke is her ex.
They need to get into the guarded archives across the street to get the sheriff's files. It used to be the armory and Crane knows a back way in. He finds the way he was looking for has been sealed off, so he hacks at the wall with the fire axe, revealing a secret passageway. It used to be used to transport weapons during the war.
He finds old crates of gun powder, right where he left them. The walls are lined with the bones of witches, who weren't deemed worthy of burial in graveyards.
In the archives, Abbie finds Corbin's files.
Andy visits a house and talks to a young boy playing soccer outside. Andy asks about this dad, and the boy says he's dead. The boy's name is Kyle Hemmington.
In the archives, Crane mentions he speaks several languages and has a photographic memory. He finds record of what happened to Sirilda. A white coven used magic to weaken her and a hunting party captured her.
Before she was burned at the stake she declared: "By the turn of the blood moon the ashes of your ancestry shall be mine. Your flesh will be my flesh, I will live again."
The magistrate who sentenced her was named Firth, like the burned victim in the car. They figure she needs the ashes of his descendants.
Kyle's mom tucks him in to bed.
Abbie traces the magistrates bloodline to the Firths and also a daughter who married a Hemmington.
Kyle hears noises in his house and goes downstairs to investigate. He finds the front door open. Charred Serilda lurks behind him.
He screams and his mom comes running. Abbie and Ichabod come in, Kyle is safe but swears he saw a woman who looked like she was on fire.
Kyle's dad's urn is missing. Kyle was adopted, the urn gives Serilda everything she needs.
Ichabod and Abbie try to figure out what Serilda needs to complete the ritual -- her own bones. They'd be buried down in the tunnels.
In the tunnels, Andy digs up a bag of bones as Serilda watches.
Abbie and Ichabod arrive and search for her.
Serilda begins the ritual with her bones and the ashes of the magistrates descendants. She lies down on top of the bones and begins to regenerate as flesh.
Ichabod arrives in time to see her come back to life. He fires with the gun Abbie gave him, but Serilda catches the bullet.
He runs for the black powder crates, thinking the gun is now empty.
Serilda talks to Ichabod about his wife, the one who bound her power. She tells him Katrina is in the world between worlds.
Crane puts the crates across her path in the tunnel and they take cover. He throws his torch and waits. Nothing happens at first, but then there's an explosion that takes out Serilda.
Later, Crane wonders if what Serilda said about his wife means she can be freed.
Crane goes to get coffee and Abbie looks towards Sheriff Corbin's office and sees him there. She thinks she's dreaming. She wonders if he was ever going to tell her what he knew, but he points out she wouldn't have believed him.
"You're so afraid of what you don't understand that it kept you from seeing who you really are, what you're meant to do," he says.
Finally, he tells her: "Don't be afraid of No. 49, that's where you'll find you're not alone."
Abbie turns around when she hears Crane. She had a vision.
In room 49 in a mental hospital , an orderly brings Jenny Mills her nightly pills as she does furious push-ups. She says she hasn't seen anything lately since she started taking the pills.
She fakes taking her pills and gets back to her work-out. The demon briefly appears in her room, but she doesn't see it and continues on, getting ready.