A vampiric Joker has fed on Etta Candy’s blood, and killed her, dropping her at the feet of a disgusted Wonder Woman. In the next chamber of the underground tunnels, Diana hears gunshots, and the Joker explains that this is the sound of Steve Trevor discovering how useless his weapons is against a vampire horde.
Diana tries to run to Steve, but the Joker intercepts her, faster because of his vampiric abilities. He explains how Batman failed to finish him off by decapitating him, even though he had thrust a stake through his heart. Poison Ivy removed it, though, and he was allowed to roam free as a monster. Diana has fewer qualms than Batman about such things, and breaks free of the Joker’s grasp to grip him by the hair and twist his head right off his neck. She only gets half-way done, because Steve fires another round of shots that make her worry for him.
Steve is surrounded by women-turned-vampires, having once been cultists worshipping the dome. While he manages to fend them off with his pistol – now empty of bullets, he finds it is useless against the likes of Poison Ivy and Catwoman. Wonder Woman arrives just in time, and when Catwoman leaps at her, she gets a mouthful of metal, thanks to the Bracelets of Submission. After first breaking Poison Ivy’s back with a sharp kick, she smashes Catwoman’s face with her fist and tries to help Steve to his feet, warning that she has yet to finish the Joker off. Unfortunately, Ivy and Catwoman rise again, along with the women Steve had beat back. Sighing, Wonder Woman realises that she can’t afford to hold back.
The Joker, meanwhile, attempts to build a splint out of bones to keep his head from flopping around. He is surprised to hear Etta Candy laughing at his appearance, turned into a vampire, since her death. While Wonder Woman is occupied with the cultists, Catwoman and Ivy drag Steve to the Joker to be turned. Diana soon finishes with the cultists, having broken their bodies to the point that they are immobile, though she lacks the tools to really destroy them. She realizes quickly that Steve is missing, and what must have happened to him. Sinking, she feels that she’s failed him, but hears the voice of the goddess Athena reminding that sometimes, monsters need to be slain, and that’s all there is to it. Whatever Diana does to these creatures is a mercy upon them – even if they are her friends.
When Diana confronts the Joker, she is far too late to stop the vampires from having fed on Steve. Ripping a splinter of wood from a coffin and tearing a bent metal cross from its stand, she thrusts each into the chests of Catwoman and Poison Ivy, dropping them to the ground. All that remain now are the Joker, Etta, and Steve.
A sudden earthquake causes the ground beneath the catacombs to split open, separating Wonder Woman from her enemies. Etta tries to leap at Diana, and unexpectedly, Steve is the one who tackles her, causing them both to fall into the fissure. As he falls, he begs Diana to watch the dawn he had been missing for a year for him. Desperately, Diana tries to loop her Lasso around him before he hits the ground, but the Joker knocks her off balance. She clings for stability as another tremor and a pile of debris knocks the Joker into the fissure as well. With his wings, he manages to keep from falling too far, and tiring of him, she warns that she will not forgive him for what he did to Steve. Tearing a sharp-ended piece of timber from the stones around her, she hurls it through his chest, and he is dead.
Diana, though, loses her grip, and nearly falls into the fissure after him, but for the helping hands of Julio, a young thug she’d met earlier. Once he and his friends get her away from the church, it collapses, and she admits that everyone inside is now dead. At least, she has solace in the fact that the people of Gotham are safe, but she can’t help but feel that the battle she won is tinged with sadness and loss.