Kyle is frantically pacing and telling Jimmy how he texted Karen about rescheduling. Jimmy is, hilariously, like, up on top of the cabinets, drinking a beer and moaning cynically about how Karen will get back to them round about never. Kyle protests that Karen isn't fake and she's going to help them. Jimmy would not trust La Cartwright as far as he can throw her, and good on him.
Derek tells Eileen they haven't had much time to work on the number, and just then Ronnie arrives with Henry, the producer on The Wiz (played by one of those silver-haired Hey It's That Guy New York actors, the kind who was both a defense lawyer and a preppy park strangler and probably also a bond trader on six different episodes of Law & Order: Original Recipe over the years). Derek explains the change of plan and says the number isn't PG, so maybe she and Henry should just go get a drink and he'll catch up with them? She says they're here, so they might as well see his work. The problem isn't that Derek isn't a proven talent, it's that he isn't a proven talent at what The Wiz needs him to do. Or what these producers of this production want him to do. But whatever. What is logic.
Derek introduces the scene: Kennedy and Marilyn attending a party at Bing's. The actor playing JFK goes very subtle on the Mayor Quimby accent when he says how pleased to meet Marilyn "in the flesh," then launches into the song, in which he's trying to convince her to leave the party with him. He gets her alone, and Julia's lyrics are just so subtle: "Outside of this room there's a cold war/but you'd never know it in here." As the song goes on, Karen takes her dress off and lies down on the bed. He comes down on top of her and the song ends.
And Jimmy starts applauding from the doorway. As everyone stares at him, Derek asks, "Who are you?" He introduces himself, and Derek replies, "Jimmy who?" Jimmy mutters, "Exactly" and leaves. Henry is also not impressed, and says to Ronnie as he walks out, "That was supposed to change our minds?" Eileen liked it, though; she tells Peter the number is the right direction. He tells Julia she proved him wrong, and they banter about does he call this an apology, he's not apologizing for anything, now that she's taken his advice, she's stuck with him, blah blah I'm just so glad he's here making things suck less.