Dick demands that Sally and Harry go to work, so she signs on as Albright's assistant and he gets a job tending bar. Then Dick decides on a career change: he wants to be cop.

Dick is annoyed that Mary, in her new position as Dean, has little time for him anymore, and is even more annoyed when he is told that he has to share is office with new professor Jennifer Ravelli. Despite his initial dislike, and attempts to stay loyal to Mary, he soon begins to fall for Ravelli. Sally tries to fix Nina up with Don's cop friend Eric, but becomes irritated when they don't take to each other. At Happy Doug's bar, Tommy fixes up an old 'love tester' machine but is disappointed when it classifies him as 'cold fish' and Harry 'hot stuff'.

As 1998 comes to close, Dick worries that he hasn't accomplished anything worthwhile and struggles to do something to make the past year count. Meanwhile, Officer Don becomes annoyed with Sally after she uses her feminine wiles to persuade him to get tickets for Rutherford's exclusive Starlight Room, then changes her mind when he succeeds. At Happy Doug's bar, Harry and Tommy plan an explosive New Year's party and Harry hires on his old night school friends, Larry and Mrs. Deguzman, but they turn out to be layabouts.

After three years, the Big Giant Head has finally accepted Sally's request to have her body changed for a man's. For their convenience, the bodies of Dick and Sally are switched. Now, in each other's bodies, Dick and Sally must try and maintain each other's romantic relationships and get accustomed to the changes that their new gender brings, while waiting for their request to be switched back to be accepted. Meanwhile, Harry is left in charge of Happy Doug's when Doug goes on vacation, but becomes worried when a group of burly, tough-looking bikers arrive.

The Big Giant Head sends a message that he intends to visit Earth, so Dick quickly orders Sally to move back in and Harry to stop attempting to make a baby with Vicki. He then attempts to prepare Mary for his visit by telling her that an 'old college chum' is visiting and that she would be well advised to discuss how much he has learned in bed. Harry tries his best to avoid Vicki, but eventually resorts to telling her that he can't father a child with her right now. When the Big Giant Head arrives on Earth, he is unimpressed with Dick, his leadership skills and his choice of girlfriend, while being impressed with Sally, her style, and her body.