With Eric going to college, Cory is looking forward to having the room to himself. He's even replaced the two twin beds with one queen-size bed. But, just as Cory is discussing his excitement with Shawn, Eric enters with news that he's not moving out.
As it turns out, Eric didn't turn in the forms needed for housing, so he's decided to stay with his parents until the problem works itself out; which it won't. Alan likes having Eric home for a little while, but Amy realizes that Eric isn't "just visiting".
Upstairs, Cory and Topanga are getting snuggly when Eric bursts in. Topanga leaves, and an angry Cory promises to find Eric a new place to live.
Cory doesn't have much luck, because Eric seems impossible to please. He and Topanga take a break at Chubbie's. When a guy announces that he's going to Pennbrook and looking for roommates, Cory tells him about Eric. He's sure everything is going to work out, until Shawn enters. "What are you doing here?" he demands of the new guy. Shawn explains that this is actually his half brother, Jack. "Same dad, different moms." Jack and his mother left when he was very young, and hasn't been in contact since. "You turned your back on your family; and on me!" Shawn declares, leaving in a huff.
Eric and Alan are playing basketball, as Mr. Feeny and Amy look on. She expresses her concern for Eric. Father and son are best friend, and neither wants to leave the other. She's nervous that Eric won't be prepared for the real world.
That night, Shawn is doing his homework, while Chet works to fix a toaster. When Jack arrives, Chet is happy to see him and proud that he is going to college. Shawn however, is not happy to see Jack, and again accuses him of bailing on his real father. With Jack looking for roommates, and Shawn never getting know his brother, Chet decides it's a good idea for Shawn to move in with Jack. Shawn refuses and accuses Chet of being a bad father.
Eric meets Jack and takes a look at the nice apartment. Things seem to be going well, and the two seem to be getting along; but when Jack leaves, Eric tells Cory, "I don't like him". Cory doesn't understand and gets angry.
The next day, Alan is getting ready to play basketball with Eric, when Amy tells him she's concerned Eric will never leave. Realizing that Eric needs to learn to fend for himself, Alan tells him he has one week to find a place to live. Shawn, who's with Cory, watches the exchange and realizes that his own father just wants what's best for him.
Jack, Eric and Shawn move into the new apartment. The fathers are sad that their sons are moving out, but they know it's for the best. Shawn looks forward to getting to know Jack, and Cory looks forward to his own room. Eric apologizes to Cory for his actions, and tosses him a set of keys. "Don't be a stranger."