Deep beneath the ocean, Harley Quinn and King Shark have just pulled off a heist for Atlantean jewels, with Clayface pretending to be Aquaman in order to call the guards off them. Aquaman himself then arrived to apprehend them, at which point Poison Ivy bound him in kelp and allowed them to flee with the jewels. Afterward, the Legion of Doom invited Harley and her crew to their headquarters to discuss potentially joining the Legion. Doctor Psycho asked if Harley could put in good word for him again after being kicked out, while Sy Borgman wanted nothing to do with the Legion of Doom. Sy also brushed over the constant, oceanic roars coming from beneath the Gotham Mall.
Harley guilt trips Ivy into coming along with the others, where Scarecrow shows them around the Legion of Doom, including its vast armaments and resources available only to members. While Harley and her crew are delighted, Ivy has nothing but disdain for the organization, even asking Lex Luthor if "L.O.D." stood for "Legion of Dildos", which is surprisingly a real sex shop down the street from the Legion of Doom with whom the Legion of Doom is in a "protracted legal battle" for naming rights to "L.O.D."
Ivy later corners Lex Luthor and demands to know why he changed his tune regarding allowing Harley in, to which he claims he is only considering inviting Harley if Ivy herself joins. Ivy however still does not want to join the "sausage fest", to which Luthor asserts they do have one woman, although he could not even remember her name. Meanwhile, Doctor Psycho is still in the Gotham Mall, annoyed by the constant roaring coming from below. Sy Borgman continues to claim not to hear it and even tries to say it is the "pipes", but when a pink tentacle erupts from the floor and thrashes Doctor Psycho around, Sy is forced to admit that there "may be a giant tentacle monster in the basement".
At the party at the Legion of Doom, Ivy tries to dissuade Harley from joining, telling her that "this isn't you". They also see Kite Man working as a caterer at the Legion of Doom, with Ivy claiming that he outclasses all of Legion of Doom members, lamenting that it is like a "boys club" or fraternity. Aquaman then arrives to crash the party and reclaim his jewels, being met with boos from members. Back at the Gotham Mall, Sy Borgman suggests simply lowering livestock down to the tentacle monster and hoping it quiets down over a few weeks. However, when Doctor Psycho insists on killing it, Sy becomes distressed and claims the tentacle monster is, in fact, his sister.
Back at the Legion of Doom, Harley sucker punches Aquaman in the throat and distracts him briefly before he kicks her aside. He then fights off all of the disarmed Legion of Doom guests with ease, prompting Kite Man to try to "protect" Ivy, but he ends up caught in a cross wind and blown away. Harley wonders why Kite Man called Ivy "babe" until Aquaman yells aloud that his quarrel is only with Harley and Ivy. At this point all of the Legion of Doom members back off except for Black Manta, Aquaman's nemesis, so Aquaman blasts Black Manta away with his trident.
As Aquaman prepares to blast Ivy, Harley baits him into attacking her, so he throws his trident directly at her, misses, and the trident strikes the fish tank she was deliberately standing in front of. With all the fish flushed out into the room, Aquaman began picking them up in distress, angrily discarding Harley's suggestion to take them to a YMCA pool down the street because these are saltwater fish. As Aquaman leaves, the Legion of Doom applauds her for driving him off.
Deep beneath the Gotham Mall, Sy relays to Doctor Psycho that he and his sister Mirielle Borgman were both in the CIA. Sy was their "go-to cleaner", while Mirielle was a scientist who specialized in grafting animals together. To help with his missions, he asked Mirielle to create a hybrid of a monkey and octopus, and although she claimed it was against protocol, she eventually made an attempt because she loved him. While securing a monkey and octopus in a chamber for merging, the monkey escaped and hit the button, trapping her inside with the octopus and transforming her into a giant tentacle monster.
At the Legion of Doom, Lex Luthor demands to know if Ivy will be joining, which she declines. Ivy then rushes to try to console Harley, and eventually is forced to reveal that the Legion of Doom does not want Harley, but actually just wants her, Ivy, and invited Harley to try and entice Ivy into joining. To everyone's surprise however, Harley is actually invited anyway despite Ivy's rejection, her performance driving off Aquaman having been satisfactory enough to allow her to join. Harley then presumes that Ivy was lying to her, and angrily goes to accept her membership. Afterward, Harley angrily accuses Ivy of wanting to sabotage her because Ivy, supposedly, has no friends of her own other than Harley. Ivy becomes angry and leaves, and although Harley initially begins to lash out at Clayface and King Shark, she is interrupted by another titanic roar coming from below the Gotham Mall. The ground beneath their feet then crumbles and Harley, King Shark, and Clayface are all dumped into the basement with the tentacle monster, Sy Borgman, and Doctor Psycho.
Confused, Harley asks why Sy is crying and why a massive tentacle monster is before them, so Doctor Psycho gives her an abridged version: "CIA experiment went wrong, that's his sister, and he hasn't been down here in like 35 years". Clayface then chimed in, saying he could not imagine what it might be like going through life a "giant, deformed thing", which, given Clayface's appearance, Doctor Psycho disbelieved. Doctor Psycho decided to "be your Whoopi" and translate telepathically between Mirielle's thoughts and Sy Borgman's words at King Shark's suggestion. Sy apologizes for Mirielle's predicament, but she claims that it was not being transformed into a tentacle monster that angered her, but rather the decades of abandonment and of Sy closing himself off to her that made her angry.
While Psycho relays Mirielle's hopes that Sy would reach out, Harley began to regret her fight with Ivy. Crying, Psycho continues translating, saying, "I always thought no matter how bad it got, you'd never give up on our friendship." This prompts Mirielle and Harley to begin crying as well, and Sy says he should have come to Mirielle but feared that she wouldn't forgive him. At this point, Mirielle then picks Sy up with a tentacle and hugs him gently. Overjoyed, Sy claims he needs no translation for the hug. He says he should never have kept Mirielle trapped in his basement and promptly frees her. Mirielle joyfully surges out of the basement and into Gotham, with Harley tearfully saying she looks "great" and seems so happy. However, Mirielle immediately begins destroying helicopters, attacking cars, and eating civilians.
Unconcerned by the pandemonium, Harley, King Shark, Clayface, and Doctor Psycho go to the Legion of Doom with their new membership cards. Although Doctor Psycho is concerned, having been banned from the Legion of Doom, his card surprisingly works. He becomes overjoyed and says to Harley that "whatever weird sex thing you had to do to get me back into the Legion of Doom, I thank you." Harley says that didn't happen and that Doctor Psycho is simply banned from any heists where they might interact with a female superhero. Harley is then tempted to reach out to Ivy, but decides against it, only to come face to face with the Joker.
Cast and Characters
- Kaley Cuoco as Harley Quinn
- Jason Alexander as Sy Borgman
- Lake Bell as Poison Ivy
- Ron Funches as King Shark
- Tony Hale as Dr. Psycho
- Matt Oberg as Kite Man, KG Beast
- Alan Tudyk as Clayface, The Joker
- James Adomian as Bane
- Chris Diamantopoulos as Aquaman
- Giancarlo Esposito as Lex Luthor
- Rahul Kohli as Scarecrow
- Phil LaMarr as Black Manta, Tenticle Monster
- Black Adam
- Calendar Man
- Captain Cold
- Felix Faust
- Gorilla Grodd
- Killer Croc
- Maxie Zeus (pictured)
- The title refers to "L.O.D.", the acronym for the Legion of Doom combined with the common phrase of "R.S.V.P." meaning "please respond" to require confirmation of an invitation.
- Lex Luthor references the movie The Martian as a comparison to him inviting Harley to the L.O.D. in order to persuade Ivy to join, stating "why did the Golden Globes nominate The Martian for best comedy? They wanted Matt Damon to show."
- Ivy comments that it's a "stupid and outdated reference".
- When Ivy tries to distract Harley from Lex Luthor announcing the new member she offers to form a group together, saying "It'll be like 'Harley & Ivy,'" possibly a reference to an episode of the same name from Batman: The Animated Series.