A stand-up comic from Detroit (Warren Beatty) owes a large amount of money to the Mafia. Rather than possibly spend the rest of his life in debt, he skips town and ends up in Chicago. Under the new name Mickey One, he gets a job at a local diner and starts working as a comic again. When his agent, George Berson (Teddy Hart), gets him a gig at a large club called Xanadu, Mickey worries that the Mafia will find him again.
Mickey One contains examples of:
- Bewildering Punishment: Mickey doesn't know what he did to incur the wrath of the Mafia, which mobster he owes money to, or even how much he owes. He has theories, like that his girlfriend at the time (Donna Michelle) was a mobster's woman, or that he took favors from criminals without realizing it.
- Desk Sweep of Rage: After Mickey flees his audition in a panic, Larry Fryer (Jeff Corey) screams at Ed Castle (Hurd Hatfield), "I want him here tomorrow! As long as he's in this town, and you booked him, he's your responsibility!" He sweeps a vase of flowers off a table.
- Disposing of a Body: One of the first things Mickey sees when he jumps off the train in Chicago is some criminals putting a body in an old car in a junkyard, crushing it with a car compactor, and sending it on to the steel incinerator.
- A Glass in the Hand: Mickey's girlfriend Jenny Drayton (Alexandra Stewart) goes to talk to Ed Castle to explain Mickey's fear of the Mafia. For most of the conversation, Castle holds what looks like a decorative glass egg. Then Jenny exclaims, "You're bleeding!" Castle has crushed the object in his hand and cut himself on the shards.
- Hobo: Between leaving Detroit and settling in Chicago, Mickey spent four and a half years traveling around, mostly by train.
- Rube Goldberg Machine: The Artist (Kamatari Fujiwara) creates an elaborate machine called Yes that seems to be made mostly out of bicycle parts. It plays a piano and cymbals, displays the word "Yes" in different languages, rotates toy cars and cubes of tin foil on conveyor belts to make it look like the cars are being crushed, spins fireworks around, and eventually sets itself on fire. Then the fire department puts it out, to the dismay of both the Artist and his audience.
- The Silent Bob: The Artist never speaks, but communicates through exaggerated facial expressions and gestures.
- Speech Impediment: Mickey goes to a mission for food, where a man with a severe stutter reads to him from the Bible.
- Starting a New Life: The protagonist burns his I.D. cards before he leaves Detroit. In Chicago, he steals a social security card that says Miklos Wunejeva, which gets shortened to Mickey One.
