It becomes a turbulent first full moon for Harley when she finds the truth about her newfound abilities, Peter's secrets, as well as the SCU hunting her and Alpha down.
Alpha is chasing Harley who is running towards a rope bridge as he calls out to try and help Harley. She turns around while transforming and blames Peter for turning her into a monster and doesn't want his help. Peter tries to reason with her, but the bridge snaps and she falls and dies. Alpha hears her ask why he didn't tell her and again when he finds her that night when the Joker stabbed her. Peter wakes up in a cold sweat discovering it all to be a dream. He goes to check on her in her room as she sleeps. He stays with her the rest of the night while preparing to finally tell her everything. The next morning, Harley wakes up feeling tired from the Magpie experience, and remembers that Ravencroft knows that she used to be Harley Quinn. As she gets up to prepare for what she believes is her last day of work, she discovers Peter sleeping next to her while holding her hand. She wakes him up and he explains that he was worried about her after last night. Harley gets ready for work due to wanting to save her reputation before Ravencroft spills the beans while Peter suggests she take the day off due to the last few nights. Harley becomes annoyed that Peter is insisting that she stay home and ruin one of her few chances for a normal life along with him keeping something from her. Peter fails and it leads to Harley becoming angry at him and leaves. She accidentally bumps into Tom Sizemore on her way out, apologizes, and heads to work while ignoring Peter.
At the Free Spirit Nursing Home, Harley is working and is relieved that Ravencroft didn't come in that day, but while still angry at Peter, regrets not taking the day off. She is visited by Hannah who heard what happened with Magpie from Jean and wanted to see if Harley was all right. They talk with Harley saying she's angry at Peter for underestimating her while Hannah accidentally reveals that Peter has had a crush on Harley since high school that she learned from Jean before leaving. Harley is left feeling confused by this new piece of info as she stares at the ceiling.
At the Everett Police Station, Rojas has all the police gathered in the main room as he states that he has enough of the costumed vigilantes and villains disgracing the police. He states that for now on, every full moon night, the SCU will be on the hunt for Alpha due to his kind having to transform against their will. He also makes it clear to Mikey and Sonia that they need to start doing their job right. In their office, Sonia is angry at Rojas focusing on the wrong threat as Mikey gets ready to go home. Mikey uses the excuse of him being a schizophrenia during the full moon due to a family condition to hide his werewolf powers while explaining some details about werewolves that he said he learned during highschool. He leaves before spilling anymore with Sonia saying goodbye to Scope.
At the Talbot Hall as the full moon rises higher, Peter is getting ready as Jean, Mikey, and Tom berate him for not telling Harley sooner. Peter knows he's a fool for not but plans to make it right by telling her as Alpha as the proof before the SCU finds her. He leaves for the Free Spirited Nursing Home as Jean is left worrying about how things will play out.
At the Free Spirited Nursing Home, Harley is looking over files while also reflecting on Peter's crush on her and is worried about ruining it. Suddenly, she feels the transformation coming over her as she stumbles to the bathroom, fully transforms, and lets out a howl that is heard by Alpha and the SCU in the area. Back with Harley, she gets up, discovers her new form, and notes that she looks like she's wearing her old Harley Quinn outfit. She goes for her torn clothes from the transformation, packs them in a bag, goes outside, and runs like in her dreams. She feels the new strengths of her form and feels more free than ever before, even as the Joker's girlfriend/sidekick. She than starts to worry how Peter will take her new fur coat when Alpha arrives to try and tell her. Things start good, but Harley starts to feel the affects of the full moon like Alpha did before and she starts to make her puppy love move on him when the SCU arrives via helicopter to arrest them. Alpha and Harley run from them leading to them grappling off a tall building into a condemned building as Rojas prepares to launch his final attack on them. In the building, Harley is feeling sick from the jump, and Alpha accidentally slips about a memory they both shared. This allows Harley to finally recognize him as Peter, punches him hard, and runs in anger from him. Alpha runs after her despite her protests not to and saying she doesn't want his help anymore as they run to a gym in the building. Alpha tries to reason with her that if she runs or is captured by the SCU, her chances of a normal life are gone, but Harley focuses more on how he waited for so long to tell her, bringing her to a werewolf hunting city, all the villain crap that keeps coming her way, and that she should just go back to being the Joker's girl since that was simple. Alpha apologizes for not telling her sooner, saying he couldn't bear being her enemy, and says to take her frustrations on him, not the town. Harley than reveals that she's more angry at Alpha for not telling him about his werewolf powers, that he didn't trust her with the secret before she left Everett years ago, and starts crying. Peter starts to explain, but the SCU breaks in, and pins them down. Harley manages to pull the grenade pins on the officer pinning her down causing a huge set of explosions to go off, sending Harley out the building and into a billboard as it falls over while she hangs on it. She believes this is the end of it, as it breaks and she falls only for Alpha to save her, but no from her lunch going all over Alpha's back.
Alpha and Harley managed to sneak back to Talbot Hall via the sewer system where they apologized to each other, Alpha for waiting so long to tell her, and Harley for comparing him to the Joker. After they both cleaned up, Alpha told her the whole story. His grandfather, Sir John, became a werewolf thanks to a hunting trip in India in his twenties. He and his group were led to a cave the mountains where they thought they would find the hunt they wanted, only to find a feral boy there who bit John's arm when he tried to help him. He and the hunters returned thinking they were the victims of a prank, only for John to turn into a werewolf in front of a gypsy woman who was an expert on werewolves. She helped John learn to control his new abilities, they fell in love, and conceived Peter's father and uncle on a new moon which suppresses the abilities of a werewolf in a human. This is what happened to Peter and how the wolf attacked awakened his wolf abilities but not Jean who was born during a lunar cycle. Different doctors saw a Jean as a werewolf puppy playing in the yard and thought it was a joke, but one believed it and tried to capture her. Peter and Jean's parents left them with Sir John and left to lure the doctor away, leading to the plane crash. Than when the wolf attacked him and killed Roland, the shock awakened Peter's wolf abilities, but didn't get the chance to tell Harley before she moved. Than he tried to stand up to Tobias, but it didn't go well, so he left to train all over the world for next time. Before he can continue, Harley starts to fall asleep, and asks to stay with her for the night as the two doze off next to each other.
In the morning, they wake up in their human forms, and than Harley slaps Peter in the face for keeping her in the dark for so long. Than she hugs him saying thanks for never giving up on her and than threatens him if he kept something like that a secret again. Peter agrees just as Jean bursts in to see if he and Harley are safe. She is relieved and reveals that Mikey, Tom, and his siblings are also werewolves. Harley realizes that there was a lot more to take in later on.
- Harley transforms into a werewolf
- Harley learns of Alpha's true Identity, as well as learns of Peter's past, and his crush on her as well.