After stealing King Tuts' own corpse, Harley still hasn’t been nominated to join the Legion of Doom, which aggravates her due to KGBeast being nominated. At King Shark's suggestion of stealing more computers, Harley becomes fixated by Wayne Tech, Batman's tech corporation. They initially steal an invisible bike, but Harley goes further and steals some sort of teleportation device. In the process, Clayface loses his arm.
Gordon throws up the Bat Signal, but actually just wants to talk about his marital problems with his wife cheating on him. Batman takes away the Bat Signal for misuse and gives Gordon Clayface's arm to interrogate. Back at the mall, Harley checks the news regarding the heist, only to find the Cowled Critic trashing her for "leaving behind" crewmembers, as well as Poison Ivy and Doctor Psycho supposedly being in a relationship after Ivy caught Psycho during his fall.
Gordon meanwhile is busy interrogating a child-like version of Clayface consisting only of his hand. He gets caught up on his marriage, which the hand is more than happy to talk about. Harley, Clayface, and King Shark prepare to break into the police department to get the hand back while Psycho and Ivy hunt down the Cowled Critic, and at the same time Gordon becomes genuinely friendly with Clayface's hand for listening to his troubles.
Harley's initial attempt to gain entry fails when King Shark is immediately tranquilized on sight and taken to prison the moment he sets food in the police station. Clayface gets away by transforming into a cop, but now he must be the distraction. He succeeds, and Harley and Clayface find Gordon atop the police building. He refuses to surrender the hand however.
Ivy and Psycho find the Cowled Critic fairly quickly, and Psycho assumes his ex wife is the critic. However, she claims to have no time to write reviews as she is usually preoccupied by her new boyfriend giving her cunnilingus (who, by demonstration, creates an ice cream sculpture with his tongue in seconds, much to Ivy's amusement). Eventually Psycho's son Herman arrives.
Back with Gordon, Harley threatens to press the button on the mystery device she stole from Wayne Tech if Gordon doesn’t release the arm, but instead Gordon shoots her, prompting her to press it. This instantly teleports her to the Batcave, where Batman is sorely tempted to let her fall to her death. However, she calls out his selfishness inputting his work before friendship, and realizes herself that she ignored Clayface's arm, making them quite similar. She convinces Batman to go after Gordon and rekindle their friendship.
Again with Psycho, Herman complains to his dad that he trapped him in basements, killed all his friends, and named him Herman as yet another insult. Psycho justifies this as simply trying to make him awful in order to become a good supervillain, and Herman claims to only have wanted to impress Psycho. They then hug, claiming to hate each other.
Batman and Harley then arrive at the police station, Batman apologizes to Gordon, and restores his Bat Signal. No longer needing The Arm, The Arm ran back to be reabsorbed by Clayface. Batman immediately tried to capture Harley then, but she used the device to teleport him back to the Batcave while Psycho disarmed the police who arrived to apprehend her. They then returned to the mall to see the Cowled Critic retract his previous review and say that Harley was good material for the Legion of Doom: if only she could stop leaving crew members behind, because King Shark is still in prison. Harley then breaks him out, finding him in fine spirits.
- Clayface tracking down his lost and independent arm is quite similar to an episode of Batman: The Animated Series where that version of Clayface created a little girl from himself, intending to have her act as a scout to see if he could come out of hiding. She went rogue and befriended Robin, forcing Clayface to track her down and reabsorb her.
- One of the prisoners at the end has the number 011285. That’s the day of the giant squid attack on New York from Watchmen, another DC property.