Broadway producer Max Bialystock is in the middle of schmoozing one of his backers, an old woman who’s mostly in it for sex, when accountant Leo Bloom arrives and beats a hasty exit at the scene. After the woman leaves, Max finds he’s still waiting in the hall and invites him in to look over the books, and takes the opportunity to rant about how he was once the biggest name in Broadway, but hasn’t been able to get a hit show going in years and is reduced to getting his money from a bunch of old ladies looking for “one last thrill on the way to the cemetary.” Leo discovers that for his last show, he fraudulently raised two thousand dollars more than he needed, but is spineless enough that Max easily convinces him to cook the books and hide it. In the process, Leo realizes that this same scam could be applied on a much larger scale, leading to potentially millions of dollars as long as the show flopped so no one would expect their money back. Max is immediately taken by the idea, and gives Leo a day on the town until he finally agrees to go through with it.
The first step is finding a play they’re sure is a loser. After hours of combing through the archives, Leo is on the verge of giving up when Max hits gold with Springtime for Hitler, “practically a love letter to Hitler” written by former Nazi Franz Leibkind. They’re easily able to get him on board, though his constantly shouting praise of the Nazis makes Leo very uneasy. With the play secured, Max spends the next several days raising a million dollars from all the little old ladies in town, and even dips into it a bit to hire Swedish bombshell Ulla as a “receptionist” who’s really just there for eye candy.
Max sets up a meeting with Roger de Bris, “perhaps the worst director who ever lived,” who turns out to be a flamboyant drag queen who’s almost totally ignorant of World War II and also quickly agrees to do the show. Next up is the actors, with an ad specifying no experience required leading to utter chaos and no suitable person found to play Hitler. But then drug-soaked hippie Lorenzo St. DuBois (or LSD) wanders in looking for another audition, and upon seeing the horrific pastiche of counterculture clichés he auditions with, Max eagerly declares “That’s our Hitler!”
The big night arrives, and the opening musical number is everything Max and Leo could have hoped for as several audience members storm out in disgust. They head for a nearby bar to avoid the furious crowd, meaning they miss when LSD actually comes on, and his wacky performance starts giving the impression that the show is actually a political satire that the audience eats up. After the show, some of them head to the same bar, and Max and Leo are horrified to hear them saying how great the show is.
Max and Leo head back to their office utterly despondent, and Leo quickly decides the only option is to turn himself in before the IRS comes calling. Max tries to stop him, but they’re interrupted by Franz, who storms in wanting to kill them for making a mockery of Hitler. After a good deal of hiding behind the desk, it turns out his gun is empty, and they all discuss what else they can do, until Max hits on the idea of blowing up the theater to stop any more performances.
They’re all so bad at the job that they end up caught in the blast and arrested, with the jury finding them “incredibly guilty.” Leo makes a passionate speech that Max didn’t actually hurt anyone with the scheme, as all the old lady backers got to feel young and attractive again, and Leo himself was pushed out of his shell to be happy and have a true friend for the first time in his life. Max simply promises to never do it again...followed by the three in prison launching the same scheme with a musical called Prisoners of Love, with Leo already outrageously overselling shares to the prison guards and even the warden.
