After summer school, Zack takes a summer job working under Arwin, but finds the job so deplorable that he tries to get one at the local supermarket, even if it means working with Cody. The revelation that London can't swim, despite her on-the-side swimsuit business, forces her to take swimming lessons from Tipton lifeguard Lance, both of whom fall in love with each other. Little does she realize that the kids at Maddie's summer camp job are the ones she has to thank for this and other tabloid gossip, and even Maddie herself begins to see the benefits of their scheme.
Zack and Cody wish on a star and get super powers. Cody gets the power to read minds and move objects with his mind. Zack gets the ability to move fast. They find their arch-nemesis to be none other than Mr. Moseby, who plans to turn all children into small adults.
The manager of a rival Revolutionary War themed grocery store challenges Zack, Cody, and their boss to a speed-bagging competition. Mr. Moseby takes in his niece Nia, in order to smooth out her sassy attitude and short fuse. When it becomes clear that Maddie's replacement Millicent finds her job much too stressful, Moseby believes that a job at the candy-counter might be the perfect remedy... until she talks London into taking her to a concert and inviting the band, their crew, and their groupies over for a wild party.
The twins get grounded and are forbidden to leave the suite, leaving London's Internet show without a producer. Luckily, Maddie steps in and books Chris Brown as a guest star on the show. Meanwhile, Cody sneaks out and books some guest stars of his own, The Cheetah Girls.