When Virginia and Burt realize they are suffering from “empty nest syndrome,” Sabrina suggests they adopt a dog. But when they are turned down by the pound, they are given a trial period as dog owners with Michael, who ends up overstaying his welcome at the Chance’s home. Meanwhile, Jimmy tries to prove to Sabrina that he’s still a ladies man, even when he doesn’t have Hope with him to attract women.
Cody offers up London's suite for a sleepover party.
Cody wants to make a positive impression with the principle on his first day of high school, while Zack just wants to hit on older girls. Cody ends up getting into a fight with the school jock/bully and sent to the principle's office. Zack ends up hitting on the school bully/jock's girlfriend and gets in a fight. London tries to adjusts going to public school by buying locker space and new friends, but doesn't go to classes. Nina promises Moseby that she will stay out of trouble but ends of getting into a fight with the school bully when she defends Zack. Everyone ends up being sent to the principle's office on their first day of high school.
Cody reluctantly helps Zack get a job with him at the Paul Revere Mini Market bagging groceries, but when their manager, Wayne, challenges the rival neighborhood mini market to a bagging competition, Zack and Cody put their differences aside in order to win.
After Arwin's mother, whom he lives with, gets re-married and moves, he finds himself way too lonely to stay there by himself and temporarily moves in with Zack and Cody. After a few days of Arwin's annoying habits, they decide it's time to give his old home a bachelor makeover and Arwin discovers the nerdy neighbor has a crush on him. Also, London is stunned after Lance breaks up with her because he realizes they just don't have enough in common.