Cody is graduating from 8th grade as class valedictorian. But Zack is horrified to learn that he has to attend summer school and tries to hide it from his parents. Meanwhile, Maddie becomes a camp counselor at a run down facility with less than ideal girls under her wing.

Cody searches for a summer job, and finds a "help wanted" sign at the local mini-mart. When the owner realizes Cody is friends with London, he will only hire Cody if he will set him up on a date with her. Zack discovers he is the smartest student in his summer-school class, all the other kids make fun of him.

The tabloids report London doesn't know how to swim, so she takes swimming lessons. Zack has been offered to work at the hotel as a plumber or to work at a local market.

Zack and Cody wish for superhero powers when they see a shooting star. Their wish comes true and they learn that Mr. Moseby is their villain, who wants to turn all kids into miniature adults.

Zack gets a job at the minimart, but has to deal with Cody bossing him around. Meanwhile, London doesn't know how to present Lance to her friends.