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.

Dick is suffering the humiliation of having been demoted from High Commander to Harry's assistant, performing the most menial jobs, while Sally has been promoted to his old role. Tommy is preparing for his high school prom with Alissa, but when the Big Giant Head insists on coming, things start to slide, especially when Vicki, who missed out on her own high school prom, turns up. After ruining the prom for Tommy and Alissa, the Big Giant Head whisks Vicki off to his bachelor pod in space.

Vicki Dubcek returns with her baby Eric Travis, telling of how she has cleaned up her act and become a proper mother. Unfortunately, however, the Big Giant Head decides to return to Earth and claim his son, but upon seeing Vicki with Eric, he falls in love with her and asks Dick to transform her hatred of him into love. Meanwhile, Harry admits that he is still in love with Vicki, but Dick tells him that he cannot have her because the Big Giant Head will punish him; whilst Tommy attempts to help Sally beat her addiction - shoes.

The Big Giant Head and his new wife Vicki Dubcek arrive back on Earth, where the Big Giant Head takes Dick to a jazz club and admits that his marriage is troubled, and that he would like to get to know him better. As his overlord becomes increasingly more clingy, Dick begins to wonder what the reason behind it is. Meanwhile, Sally gets the wrong idea when she hears Alissa giving Tommy advice about his Valedictorian speech, and saying that it is a time to move on, and so, thinking that Tommy is about to get dumped, she finds Alissa and breaks up with her on his behalf. Harry finally asks Janice out on a date and the pair get together after a meal at the gym; however, Vicki is jealous, her old love for Harry stirring admits her troubled marriage.

The Big Giant Head has revealed to Dick that he is his father, and so would like to get to know his girlfriend Mary better; however, Mary gets drunk at the dinner party and reveals that she has slept with over forty men in her lifetime. The Big Giant Head orders Dick to break up with Mary so he decides to run away with her, before Tommy reminds him that Earth children defy their parents all the time. Meanwhile, Vicki invites Harry's new girlfriend Janice to Tommy's graduation, where she attempts to kill her from beneath the bleachers; however, Sally quickly realizes what's going on and rushes to intervene before it is too late. The time comes for Tommy's speech, but he puts aside talking about his achievements to try to convince Alissa to forgive him.