Jimmy Barrett is a sharp-tongued celebrity comic and the husband of Bobbie Barrett, his manager. At a Sterling Cooper promotional shoot for Utz Potato Chips, Jimmy compares the company owner's heavy-set wife to the Hindenburg and compounds the insult by refusing to apologize. Don Draper's attempts at damage control include sleeping with Bobbie.

At first unaware of the affair, Jimmy thanks Don for resolving contractual issues complicating a television deal. Jimmy soon becomes suspicious, though, and at a party to celebrate the TV show he tips off Betty Draper about her husband's infidelity. Later the same evening he confronts Don directly. "You're garbage," says Jimmy. "And you know it."

Not long after Jimmy's revelation to Betty, the two men run into each other at an illegal gambling club, where the comedian greets Don as "The Man in the Grey Flannel Suit." Don decks Jimmy with a single punch.