Abbie and Ichabod are on a quest to find a weapon of ultimate power to kill Moloch - the Sword of Methuselah - before the Headless Horseman can stop them.
- Abbie and Crane search for a weapon capable of defeating Moloch and (nearly) come face to face with a creature from Greek mythology. Crane is also forced to confront the fact that entire direction of his life has been influenced by his former best friend Abraham, currently riding headless as the Horseman of Death.
The episode is designed as a test of the Witnesses' belief in themselves, but enjoying a show in which Benjamin Franklin and George Washington led a secret movement to stop the dark forces of evil from rising already asks the viewer to press pause on any doubts. The series' mythology requires the viewer to be all in, just as Crane and Abbie are in their quest. So while the doubts may be perfunctory, the challenges, as always, are not. With echoes of "Indiana Jones and the Last Crusade," tonight, Abbie and Crane are forced to choose wisely.
In the archives, Abbie and Crane take a game break because they're stumped going through Abbie's mom's journals for clues.
Karina mirror-conferences in with them to report she's failed so far in killing Moloch and at the rate he's growing she thinks he'll be able to rule the world in two days. Crane starts to tell her about a weapon that could defeat him, but she has to end it when she hears someone coming.
Later, Henry uses his magic to essentially retroactively eavesdrop on the conversation.
Crane has a breakthrough and decodes the journal to read a clue pointing them toward "Enoch's sword."
Abbie gets an alert that Captain Reyes is sending a task force after Captain Irving, whom Jenny is busy driving to the Canadian border. She warns Jenny.
Back in the archives, Crane finds reference to a sword of Methuselah that can kill any demon in the book of Enoch. Another clue leads them to Benjamin Franklin's famous "Join or Die" poster, the snake shape of which matches up with a river on a local map. They think the tip of the serpent's tongue points to the location of the sword.
They find a prophesy: "Know thyself completely. Perish when you attempt to see."
Unfortunately, Henry has watched their entire exchange secretly through the mirror. He sends Abraham to retrieve the sword before they can.
Before Abraham leaves, he tells Katrina what he's doing and that they'll celebrate Moloch's rise when he returns.
On the road, Jenny and Irving hit a road block. Irving gets out of the car with plans to regroup with Jenny on the other side.
In the woods, Abbie recognizes the rubble of a nearby building from her dream about her mother in Purgatory. They're forced to hide when Abraham rides up. Crane wants to wait for daylight to fry the Horseman, but Abbie charges ahead, worried he'll get the sword first.
The Horseman turns away from the sword's location when Abbie accidentally knocks over a brick. He stalks her down and Crane jumps out to draw his fire. Crane hides as the sun begins to rise. The Horseman starts to smolder and gets on his horse and rides away.
Crane remembers back to England, when his best friend Abraham talked him into joining the army and going to the colonies. Crane expects the prophesy about knowing himself completely will apply when he inevitably faces the Horseman of Death again.
Crane explains just how influential Abraham has been in his life. Flash back to them having drinks in bar when Katrina joins Abraham and shares sparks with Crane.
Back with Abbie, he wonders how he's supposed to know himself when all of his life choices have been guided by Katrina or Abraham.
Abraham took a plaque containing a clue, but Abbie describes what she saw and they find a hidden staircase leading to a giant cavern filled with stone statues in frozen poses, shielding their eyes. A monster slithers about on the ceiling above them. Crane puts together that they aren't statues, but real people. They run, being careful not to look back. They slam shut the metal door with the monster on their heels.
They're dealing with a gorgon (think Medusa) a monster that turns anyone to stone who happens to look upon it.
Abbie is upset that one of the stone figures was her Dixon ancestor. She suggests that someone with no eyes might be able to retrieve the sword.
Meanwhile, Jenny gets a message from Irving that he won't be rejoining her and has chosen to fight alone.
At Frederick's Manor, Henry reveals to Katrina that he has found her poison intended for Moloch and he allowed her to contact Ichabod through the mirror. Then he lifts the enchantment so she can see Moloch and the decaying mansion around her.
Late at night outside the secret cavern, Abbie and Crane wait for the Horseman to appear. They're hoping he can take on the Gorgon while they search for the sword. When the Horseman arrives, they lure him into the cavern where the Gorgon quickly goes after him.
They race into another chamber and find two dozen swords surrounding a basin of water. Abbie has to chose the right one while Crane goes off to face the Horseman, who has defeated the Gorgon.
Crane is able to see Abraham due to the prophesy about everyone wearing their true face before the sword. Crane challenges him to a final duel. Abraham rages that he was supposed to be the hero of the story not the villain, but Crane has driven him to be the bad one. He taunts Crane about Katrina always coming back to him.
Crane holds him off but finally runs for Abbie, calling for the sword. She picks one. All the others turn to snakes. But then so does the one in her hand. There's no sword.
Abraham quickly bursts in on them and takes aim with his shotgun. He's about to fire when he hears the horn signaling the rise of Moloch calling him. Crane taunts him to run to his master, but instead of being cowed or shamed, Abraham embraces the fact he's the Horseman of Death and leaves Ichabod to a lifetime of hell knowing that his wife is with Abraham.
Left alone, Crane wonders if he can't see the sword because he doesn't know himself. Abbie talks him out of it and they return to the prophesy: "Know thyself completely. Perish when you attempt to see." Crane looks at the basin of water that was in the center of the swords. They discover it's oil. Crane sticks his torch in it, but it goes out.
Then they decide to try together. They each grab a torch and dip it in the oil. It reveals the sword inside. Crane grabs it, triumphant. "We shall not witness the apocalypse on this night. Moloch shall not rise," he says.
Meanwhile, Henry, the Headless Horseman and Moloch prepare for the ceremony that will bind Katrina to Abraham, and bring about Moloch's rise.