After Diane leaves Cheers for a "vacation" Sam reverts back to his old ways of drinking. Coach hates to see him this way, because he remembers what it was like the first time. So he turns to Diane for help.
Cliff meets a woman at the Costume Party at Cheers who he really likes, and she even likes him back. But after the night ends he is afraid to see her again without the mask.
The wedding is set, and everyone's excited. That is until Irene (coach's fiance) wins the lottery and dumps him. When Coach refuses to believe that it has really happened the gang worries he is in a state of denial.
Diane meets Frasier's mother for the first time, who "casually" tells her she will kill her if she doesn't leave Fraiser alone.
Nick, Carla's scumbag of an ex-husband, returns demanding a more equal division of the marital properties. Namely he wants one of the kids, a demand to which Carla actually agree's.
Diane moves in with Fraiser and begins to suffer from a mysterious allergy, which Fraiser believes is a subconsciencious sign that they are not ready to live together.
Sam becomes attracted to one of Diane's friends, but she strongly insists he stays away. Which of course only makes Sam want her more. After their first date the girl already wants Sam to meet her parents, or who she calls him, "their future son-in-law".
Diane insists the gang include Fraiser in their "Masculine Pursuits". So they take him on a "snipe" hunt in the woods and leave him there as a prank. Which doesn't go well.
Sam agree's to be the pitcher for a charity softball game against Playboy bunnies, but being back on the mound brings back his competitive self and he strikes them all out.
Cliff is a little too ill to finish his mail route so Norm does it for him and gets arrested because of it. But Cliff's pride and fear of losing his perfect discipline record makes him refuse to back up Norm's explanation to the cops.
Sam tries to hit on a lady who works as an investigator for the Boston singles scene; too bad she has heard every line in the book.
An old friend of Sam's returns to the bar with some interesting news. He reminds Sam of an old bet, which stated that if Sam didn't marry Jacqueline Bissett before a certain date he would have to give the bar up.
Nick, Carla's ex-husband, comes to Cheers begging for her to take him back after Loretta kicks him out of the house.
Sam throws Diane a going-away party after she announces she will be leaving to acompany Fraiser to Italy for a while.
Carla insists that Sam higher an older woman to replace Diane to avoid the love factor, which Sam does. But he can't control his attraction to her young daughter, a factor Carla didn't add in.
Carla rounds up all of her former classmates from "St. Clete's School for Wayward Girls" to plot a long awaited revenge to an old principle she spots drinking at Cheers.