Sam agrees to be Carla's date for her ex-husband Nick's wedding. And Sam's appearance makes Nick jealous, and causes him to ask Carla to take him back.
A man in the bar becomes sick of Cliff's obnoxious know-it-all behavior and challenges him to a fight. Will Cliff shut up, accept the challenge, or run away?
Carla has everyone convinced that the bar's new fortune-telling machine can predict the future. But does that include Diane's fortune that seems to indicate that her relationship with Sam could be in trouble?
Sam says he's going to Vermont for a funeral, but Diane knows he's really going on a ski weekend with his buddies. And Cliff gets jealous of Norm's new friendship with another guy.
Diane follows through with getting her portrait painted behind Sam's back. But the artist predicts that if she shows it to Sam, she will never see him again.
Sam falls off the wagon and Diane has a nervous breakdown after the breakup. But after she's cured, Diane returns to Cheers to recommend her psychiatrist--Dr. Frasier Crane--to help Sam. But she doesn't say that she's involved with him.
Diane tells Sam that she's seeing Frasier. Then, they both confess that they no longer have feelings for each other, even though both suspect the other is lying. And since the feelings are supposedly gone, Diane takes her job back.
Frasier tells Sam that the girlfriend of one his "clients" called out another man's name in bed, but Sam knows he's talking about Diane. Meanwhile, Cliff is afraid to tell a burly colleague that he's the fellow mailman who got him fired.
Cliff meets the woman of his dreams at the bar on Halloween night but is afraid of meeting her when he's not in costume, and Sam and Diane have their first non-romantic outing together after the breakup.
Sam accidentally shoots himself in the rear end after a confrontation with a jealous husband, but he changes the story when he tells it to the bar to make himself look like a hero.
Diane tries to make a good impression on Frasier's mother. But after their first meeting, Frasier's mother warns Diane that if she continues to see Frasier, that she will kill her.
Diane develops an allergy believing it's Frasier's dog after they move in together, but Sam and Frasier know her allergies are psychosomatic. Meanwhile, the guys at the bar shower Carla with a series of gag birthday gifts.
After a health scare, Norm gives up his old life and says he's moving to Bora Bora. However, he chickens out at the last minute and hides out in Sam's office. Meanwhile, Carla becomes depressed after losing a tip wager with Diane.
Diane warns Sam not to go out with a friend she met at the mental hospital because she has obsessive issues with men. But Sam doesn't heed the warning, and puts himself in a situation that he's afraid to get out of.