Batman, using retractable wings in his suit, flies over to an abandoned warehouse to confront Harlequin, a deranged murderer who kidnaps people, kills them, and then mutilates their corpses or turns them into toys and taxidermy with freakish grins. He enters and finds sinks filled with blood and a refrigerator with frozen corpses, heads and limbs. Upon entering the basement, he finds several crates, clown themed items and large jack-in-the-boxes, one with a top half of one of Harley's victims. When he finds and frees her latest captive from the third box, Harley enters, enraged at Batman depriving her of a victim, attacks Batman with a large mallet, driving him back, as Harley swings it and swats him through the air when he tries to pounce on her from the ceiling. An intense combat sequence ensues, wherein Harley takes up a chainsaw against Batman, having been disarmed of her mallet, which she strikes against a wall and accidentally destroys along with some of her rotting, human taxidermy while slashing at Batman. Harley, having wounded her abdomen when her chainsaw was destroyed, gives up the fight and permits Batman to take her to prison. However, instead of handing her over to the police, Batman, revealed to have retractable fangs and vampiric hunger, bites her neck and drinks her blood.
Brainiac is destroying Metropolis with an immense, red energy field that threatens to wipe out the entire East Coast. Since the government is unable to contact Superman, Doctor Sivana recommends that President Amanda Waller order a nuclear strike on the city. Sivana muses out loud that it is ironic that the government needs Superman's help in destroying Brainiac, who was created by the government in an attempt to check Superman's power. Waller reluctantly orders the strike. Before the bomb is dropped, Superman intercepts the bomber and scratches words on his cockpit window, asking him to be given 5 minutes in order to stop Brainiac. Superman flies to the city and struggles against extreme forces and wind generated by the field as he walks towards it. After going inside the energy field, Superman finds Brainiac is a small, mutilated, cybernetic, distraught child who does not know who he is, says that he got away from someone, and that he cannot control his powers. Superman states that he had learned to control his powers when he himself was a child and says that the child must concentrate. Unfortunately, the sobbing child finds himself unable to, driving Superman to believe that he must kill the child to stop him before its too late. The child, also coming to this realization, pleads for Superman to stop him. Superman uses his heat vision to kill Brainiac and the energy field subsides. Superman then sighs in relief, but is saddened by what he had to do.
Steve Trevor is sent by President Waller on a mission to stop Kobra from unleashing an unknown super-weapon on the world during Amanda Waller's inauguration, by launching it inside a rocket capsule. Before Steve is executed by Kobra at gunpoint after being captured, Wonder Woman, using the Mother Box from her sword to find him and create a Boom Tube to teleport to his position, manages to save Steve. Together they defeat Kobra and his henchmen in an intense firefight. As Wonder Woman kills the Kobra Leader with her sword, he presses a detonator that activates the super-weapon, revealed to be Giganta, a blue, towering, female-shaped battle robot that bursts out of the rocket capsule. Due to Trevor's previous insistence that he can handle the mission alone, Wonder Woman does not intervene in the fight while Trevor is repeatedly defeated by Giganta. When Steve is almost crushed in Giganta's hand, he finally asks for help, leading to Wonder Woman cutting off the robot's right arm, saving Trevor, but she is then pummeled into a wall and thrown aside. Giganta pulls off a piece of the metal wall to crush Wonder Woman under while the latter summons her sword telekinetically to her hand to teleport away. Giganta then seemingly crushes Wonder Woman under the piece of wall and steps on her before she turns on Steve once more. Before she can kill him, Wonder Woman, who had used another Boom Tube from her sword to escape being crushed, teleports onto Giganta's head and pulls out wiring in her brain, disabling her permanently. Before Steve Trevor is able to call Waller to tell her that the mission was a success, he is stopped by Wonder Woman, who proceeds to crush his phone and rip off his damaged shirt, implying that they are about to make love right there and then. Steve jokingly asks Wonder Woman "Am I gonna need a safeword?".