Cody finds out that he is valedictorian of his 8th grade class, while Zack is horrified to learn that he can't graduate because he failed English. Meanwhile, Maddie accepts a summer job as a camp counselor but soon finds herself in over her head.
Cody looks for a summer job. He sees a "help wanted" sign at the local mini-mart. The owner of the mini-mart says that if Cody gets him a date with London, he'll hire him. Meanwhile, Zack discovers he is the smartest student at summer school and that all the other kids hate him.
The tabloids report that London doesn't know how to swim - which is a problem because she sells a whole line of swimsuits. She decides to take swimming lessons, and gets a crush on her instructor. Meanwhile, Zack tries to figure out what he's going to do what he's going to do for his summer job.
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 is embarrassed to introduce Lance to her friends.
When a competing minimart issues a competition to see who can bag items faster, Zack and Cody accept the challenge. Meanwhile, Mr. Moseby's niece Nia is goofing off with London.
To try to impress Stacie, Cody tells her she can have her birthday sleepover in London's hotel suite while she is away.
Zack and Cody invite Arwin over for dinner. Unfortunately, he won't leave. Carey gets annoyed so she tries to get Zack and Cody to make him go. Meanwhile, Lance dumps London and she wants to find a way to get back together with him.
Maddie and London both audition for the role of Sharpay Evans in a school stage production of "High School Musical". Carey and Mr. Moseby try and help improve London's singing and dancing.
It's the first day of high school for Zack and Cody. For the first time, London has to attend public school.
Zack tries to negotiate a better contract for Carey as the Tipton's nightly singer. After losing her science tutor, London asks Cody to help her with her project. Nia also wants Cody's help so she bribes him with concert tickets.
London throws a Halloween party. Zack and Cody accidentally let a monster-like robot loose in the hotel.
Maddie is back and is not getting along with Nia, while Esteban is not getting along with Patrick, and the rest of staff aren't getting along either. Mr. Moseby hires a professional to help the team get along. Meanwhile, when Zack causes some customers to leave, he and Cody schedule a bug convention at the Tipton to make it up to Mr. Moseby. Unfortunately, the bugs are released throughout the Tipton.
Cody gets jealous when a famous teenage Russian violinist joins the school orchestra and flirts with Barbara. London tries to learn about the hotel business.
Zack and Cody both each invite a girl over to their father's empty apartment without the other's knowledge. London teaches Esteban to act wealthy after his family seizes power in his home country.
Cody helps London with her online video website. Meanwhile, Zack and Mr. Moseby become addicted to a video game.
Tony Hawk stays at the Tipton Hotel. Zack and Cody have to work on their science project together about germs. When Zack finds something interesting in the kitchen, he gets the whole Tipton and Cody worried. Meanwhile, Maddie and London's fencing instructor causes them to develop a crush on him.
Zack and Cody befriend Travis, a kid whom they rope into helping them impress their dates. Maddie finds a stranger's phone and suspects it belongs to her crush, David.
London doesn't make the cheerleading squad, so London, Cody and friends decide to form their own cheerleading squad. Meanwhile, Zack is having some trouble on the basketball team.
Maddie, Cody and Zack compete to get the best guest for London's online chat show. Luckily, The Cheetah Girls and Chris Brown are staying at the Tipton.
Carey soon discovers that she is the ship's lounge singer when Zack and Cody surprise her with a cruise vacation. A 24-hour Web-show marathon is conducted by Mr. Moseby, Maddie, and London, who are trying to raise money for the homeless.
When Mr. Tipton comes to the Tipton, he plans to fire someone from the running. As Mr. Tipton chooses, the entire hotel crew remembers the good deeds they did, and how they really don't want to be fired.