Abbie and Ichabod drive to Fredericks Manor after recovering the Sword of Methuselah, as a storm brews overhead. Ichabod hopes that Katrina can hold Moloch off long enough for them to get there. A lightning bolt hits the SUV and shorts out the ignition, and they coast to a stop at a nearby station. The mechanic says that it will take an hour to repair once they get the parts. As he goes to call them a cab, another lightning bolt strikes nearby as the storm builds. Ichabod spots a motorcycle and figures that the justification is sufficient to steal it. They grab the sword and take off.
The Witnesses arrive at Fredericks Manor and realize that there's no lights inside. They enter the house and look around, and find Henry's model of the town. There's no sign of anyone, and the flaps on the model indicate locations where Henry has struck. Ichabod lays out string along the points and discovers that it forms a pentagram over the city. Abbie saw a similar pentagram in Moloch's lair in Purgatory, and Ichabod remembers that Washington's Bible says that a demon will start the Apocalypse by creating Hell on Earth.
Katrina calls out and Ichabod and Abbie run to the back. The Horseman is stringing her up for the binding ritual, and Ichabod takes him on using the Sword. It's strong enough to shatter the Horseman's Axe, and Ichabod knocks his opponent to the ground while Abbie frees Katrina. Ichabod orders the Horseman to tell him where Moloch is, and Katrina extends the amulet's enchantment so they can see Abraham's face. He knows of the Sword and reminds them that all magic has a cost. If someone kills using the Sword then their soul is forfeit. Abbie and Ichabod don't believe him, but Katrina warns that the runes on the blade may confirm what Abraham says.
The trio take Abraham to the archive containment cell and wait for Jenny to arrive with the research Katrina needs. Until then, Katrina will have to interrogate him. As they watch Katrina chain Abraham in the chamber, Ichabod admits that their marriage has been under a great deal of strain, and considers killing Abraham despite the cost. Jenny calls and Ichabod and Abbie go to meet her.
At the cabin, Jenny shows them the passage confirming that Abraham spoke the truth. Abbie suggests that perhaps they will have to sacrifice their lives to kill Moloch and Henry, and asks if Ichabod can kill his son. Ichabod insists that Moloch is the primary target, but Abbie isn't convinced. Jenny suggests that if someone's soul has already been claimed then the Sword can't consume it. Since Henry owns Irving's soul, Irving may be able to wield it without dying. Abbie points out that Irving has a family and they don't know where he is, but Jenny says that they have to take the risk.
In the forest, Henry and Moloch go to the spot where Moloch pulled Henry from the ground. Moloch begins to create an opening to Purgatory.
Katrina reminds Abraham that she saved his life and Moloch abandoned him. Abraham dismisses her as a spy, and says that the binding ritual was the last resort. Katrina insists that she set out to destroy Moloch, but when she was with Abraham she saw the real man. Ichabod enters the observation gallery as Katrina admits that she cares for Abraham, and gets Katrina's attention. She enters the gallery and Ichabod has her confirm that Irving can wield the Sword. Katrina offers to stay and convince Abraham to speak, and Ichabod coldly says that he'll go. She asks if he trusts her judgment, and Ichabod asks his wife if she could kill Henry if it was necessary. Katrina points out that if they kill Moloch then Henry's soul will be free, and insists that there is always another way. Considering, Ichabod leaves without another word.
At the cabin, Abbie tells Ichabod that she's found a reference to the Sword in the book of Genesis. Ichabod assures her that he will kill Henry if he has to, just as Jenny replays Irving's message to her. He leaves a code at the end, 9-23, and Ichabod remembers that on September 23, 1780, spy John Andre was captured and taken to the old military post downtown. Ichabod asks Abbie to go back to the archive while he and Jenny investigate the post.
Ichabod and Jenny make their way through the tunnels to the post, and notice a tripwire just in time. Irving comes up behind them with a shotgun, and Jenny says that they need him. They explain about the Sword, but Irving wonders what will happen if they're wrong. Ichabod points out that if they are then Irving will serve Henry regardless, and Irving says that he needs to see Cynthia and Macey one more time. When Jenny warns that there isn't enough time, Irving makes her promise that she will look after them. When she does, he takes the Sword.
In the containment chamber, Irving demands answers from Abraham. Abraham wonders if he's willing to give his life to kill him, and Irving points out that Henry has already claimed his soul. He cuts Abraham's arms and the skin burns, and Abraham says that War and Moloch are opening the gate to Purgatory at the Four Trees. The blackening of the first white tree brought lightning, the second will bring blood. The third will bring Moloch's demon army, and the fourth will complete the formation. Abraham dares Irving to kill him, and Katrina says that they may be able to use him later. Ichabod agrees and says that they need to focus on Moloch. Jenny says that they need more weapons, and Ichabod asks what she has in mind.
Nick is drinking at a biker bar when Jenny and Ichabod come in, and he realizes that they need him. Ichabod tells him that Moloch has risen, and Jenny says that they need every weapon in Nick's arsenal. He points out that everyone in history has been wrong about the End of Days, just as it begins raining bloody hail. Nick admits that he's right and goes to get his weapons.
Later at the archive, Nick hands out the flintlocks of Blackbeard, and an enchanted katana. Katrina confirms that they are enchanted but she will require some time to revitalize them. Nick asks about Abbie and they tell him that she's with the Horseman. They take him to the containment chamber and Nick agrees to watch over Abraham and fight any demons sent to break him out.
In the archive, Ichabod tells Katrina that he heard what she said to Abraham about caring for him. She assures Ichabod that she loves him but worries that he doesn't trust her. Ichabod points out that she left without any notice and failed to kill Moloch, and Katrina has lied to him about so many things. Katrina suggests that they consider themselves as soldiers and nothing more, and Ichabod agrees. The others come in and Katrina tells them that the weapons are ready.
The third tree burns and Moloch grows impatient with Abraham's absence. He blames Henry for letting Ichabod and Abbie getting the Sword, but Henry insists that it was Abraham's failure. Moloch says that he shall send the first of his army against them with War, and Henry concentrates as the army rises in Purgatory.
As they head through the forest, Ichabod tells Abbie about what he and Katrina decided. Moloch's demons open fire and one of them wounds Abbie. Irving kills one with the Sword, and Katrina repels another long enough for Ichabod to kill it. He disposes of a third one while Jenny takes Abbie to the nearby church, and Irving kills another demon. The Horseman of War arrives and Irving goes to face it, cutting off its arm after a brief fight.
At the Four Trees, Henry clutches at his arm in pain.
The Horseman kicks Irving back and grabs its sword with its remaining arm, and manages to cut him. Irving finally drives the Sword home and the Horseman melts into slag. Ichabod yells for Katrina and she tries to heal Irving's wounds. She warns that with the merging of the worlds, she can't stop the bleeding. Ichabod tells Irving to fight, but he dies.
Ichabod and Katrina enter St. Henry's Parish and tells the sisters the news. They bring Irving inside and Ichabod says that they must soldier on in Irving's name. He promises that Irving's sacrifice will not be in vain, and Abbie picks up the Sword and says that she'll kill Moloch with it. Ichabod says that he won't lose another friend, and that it is his destiny to wield the Sword. Abbie says that they'll win together and she'll wield the sword. If she falls then Ichabod will pick up the Sword. Katrina and Jenny promise that they will take it up if Ichabod falls. Abbie says that she is not going to let Moloch take another soul. When Ichabod admits that she's right, Abbie says that he hasn't heard her plan yet.
Moloch tells Henry to retrieve the Sword. When he points out that he has no power, Moloch says that he will serve as a distraction. Shocked, Henry says that he is a Horseman, but Moloch tells him to be grateful for the chance to sacrifice himself for Moloch's glory. He tells Henry that they're at the church, and glares at Henry until he goes.
Henry enters the church and Abbie steps out to confront him. He assumes that Ichabod is hiding and says that they've already lost, and animates roots to entangle her. As Henry reaches for the sword, Jenny shoots him in the shoulder with one of the flintlocks. He smashes her back and entangles her as well, and Katrina dispels the illusion on the blade, revealing that it's a harmless weapon. Ichabod steps out and places the Sword to Henry's throat, and Katrina tells her son to step aside so that they can deal with Moloch. Henry seals the doors and says that if they want to leave then they'll have to kill him.
Abbie tells Ichabod to do it, and Ichabod relates the story of the Akeda, of Abraham and Isaac. He says that God sent a ram to be sacrificed in Isaac's stead, and he begs Henry to let him pass so that he can kill Moloch at the cost of his own life. Henry will then be freed to live a life in a world of free will. Henry, shocked that Ichabod would give his life for him, stares in surprise at his father. He realizes that Ichabod never gave up on him and never will... and then chokes Ichabod, grabs the sword, and casts him aside. He tells them that Ichabod's compassion has defeated him once more and orders them to come with him to Moloch.
At the Four Trees, Moloch binds the four prisoners. He tells Henry to kill Katrina so that the fourth tree will burn. Henry points out that Abraham made his bargain for Katrina, and Moloch dismisses Abraham and Henry as nothing but what he made them. After a moment, Henry turns to Katrina and prepares to strike. Ichabod tells Henry to kill him, and Henry says that God designed a cruel and merciless world. He wonders who could worship a deity that would command a father to kill his son, and believes that any man willing to sacrifice his child should die. Henry then turns and stabs Moloch with the sword. Moloch explodes into flames as the others stare in shock.