Sam couldn't stop the wedding, but Frasier tells him that Diane left him at the altar and is now working at a convent. So Sam visits Diane to ask her to come back to Cheers. Meanwhile, Woody replaces Coach and become Cheers's new bartender.
The gang at Cheers flies Woody's old girlfriend in from Indiana to visit, and it becomes obvious that when they're together they use binge eating to curb their sexual urges. Meanwhile, Frasier takes a job at Cheers to make Diane feel guilty.
Sam accidentally convinces Carla's son Anthony to get married, Cliff is convinced that he's grown a potato that looks like Richard Nixon, and Diane blows her opportunity to get a part-time position at the university.
Diane uses Sam as a case study for a paper in her Human Sexuality class, but she paints an unflattering picture of him. Meanwhile, Woody challenges Carla to a sports trivia contest, and Cliff grows a unique squash.
Diane convinces Sam to go to Frasier with fake depression symptoms so that Frasier can analyze him and get his confidence back as a psychiatrist. But Frasier comes back with a diagnosis that Sam's depressed because he's still in love with Diane.
Councilwoman Eldridge tells Sam to fire Diane because she's insecure about having one of Sam's former lovers working at the bar. However, Diane accidentally overhears the conversation and tries to beat him to the punch.
Councilwoman Eldridge presses Sam for a marriage proposal, but Sam remains noncommittal. She then dumps Sam after he and Diane create a scene at her press conference. The incident leads Sam to a proposal--but to whom?