To impress a cute academically-minded boy, London tries to pass herself off as brainy with help from Maddie. Meanwhile, neatnik Cody moves out of the room he shares with sloppy Zack and transforms a closet into his very own bachelor pad.
The French Ambassador is staying at the hotel with his daughter, Jolie. Zack and Cody both want to win her affection. Cody wins. In the end, Bob gets her though. Esteban is upset because in the process of trying to save London from a Bag stealer, he gets beat up and London knocks the bag stealer unconscious. Without telling Esteban, London and Maddie plan to set it up again using Arwin.
The Tipton's chef walks out (again), leaving a more-than-willing Cody to do all the cooking. Unfortunately, he, and his personal crew, must prepare a spectacular meal for a restaurant critic who isn't what he appears to be (literally).
Zack and Cody beg their mom for a pet, so she gives them rocks. They hear that the horse man for the Tipton is retiring. Mr. Moseby is planning to sell Tippy the Horse to a "nice" man from Vermont. The twins overhear the man on his cell phone saying that he is using Tippy as a workhorse. The twins hide Tippy in Arwin's shack, but he gets loose in the hotel. Moseby makes the twins find Tippy before he does or their mom is fired. They find Tippy and let him sleep in their room for the night...BIG MISTAKE!
When Zack and Cody run against each other for class president, they find out who their friends (who have to be bribed to vote) really are. Maddie acts as Cody's campaign manager while London teams up with Zack. Since Zack's team has virtually unlimited financial resources for his campaign--while Cody tries honesty to win over votes, it's naturally a landslide in Zack's favor.
Moseby's older brother stays at the Tipton. Moseby has been ostracized by him since childhood, but soon discovers that his brother is bankrupt. Moseby tries to help him by giving him a job at the Tipton. Meanwhile Zack and Cody save their money to buy a single bike, which they must share. Zack ends up using the bike more than Cody even though Cody put up most of the money.
Cody's extracurricular activity is canceled at school, so he decides to join wood shop. Zack is also in wood shop and excels in it. Cody on the other hand does not. London and Maddy have to write a short story for school. London steals the story from Maddy and refuses to admit that she stole it.
When Maddie and London schedule their Sweet-16 parties for the same day, Maddie tries to talk London into rescheduling hers (It's not even London's birthday) for a different day, since they share the same friends. London doesn't budge. On top of that, she plans a spectacular party at the Tipton, with gifts for the guests (like plasma TVs) and great food, while Maddie, well...you know Maddie. All the guests (except Zack) show up at London's party for the free stuff, while only Zack makes it to Maddie's party ('cause we all know how much he loves her). But Maddie isn't ...
While Cody is preparing for the Boston Spelling Bee, Zack tries to borrow money from his mom for video games. When his mom won't give him money, he borrows from everyone else in the hotel. He finally borrows $30 at 20% interest from a rather large bully. He tells Zack to pay up, "or else." After Cody and the bully become the final two contestants, the bully offers Zack another out: get Cody to lose, "or else." Zack realizes that he should let Cody do his best. It turns out, however, that the "or else" isn't being beaten up- it's having his mom find out.
The Tipton employees compete against the St. Marks' employees. They decided to play bowling. Zack is a great bowler and could lead them to victory, but he gets into some trouble and his mom kicks him off of the team. Who will come to their rescue?
"Don't play hockey in the lobby", "eat your veggies", "it's time for bed". Zach & Cody are tired of being told what to do all the time. Serendipitously, Arwin has created a Parallel Universe thingy, which the boys inadvertently use to transport themselves to a, um, parallel universe. A world of all-you-can-eat candy, all-you-can-watch-TV, and a no-rules-ever Mom. Paradise? Let's see.
Cody's been tapped to be the editor in chief for the school newspaper but when Zack begs for a position on the paper, the only job that is left for him is the advice column. Then Zack uses his position on the paper to benefit himself.
Part 1: Raven steps up to organize an important photo shoot showcasing Donna Cabonna's new fashion line for boys at the Tipton Hotel in Boston. After a mishap, she must substitute the fashion models with Zack and Cody. When the reclusive photographer Pistache gets stuck halfway around the world, Raven's got to think quickly to save the photo shoot. Meanwhile Cory and Eddie try to get Chelsea to break the record for the world's longest paddle ball session so they can claim the prize money. They think they have the record in the bag until Stanley proves to be a ...
When Carrie starts dating a 'New man' Cody calls his father to stop them from dating. But Kurt has other intentions with her boyfriend. London joins Maddie's volleyball team and in order for her to play well, Maddie must take drastic measures.
A wheelchair basketball team visits the Tipton and plays against Zack and Cody's team in order to raise funds for their school. Zack and Cody try to invite an old friend of theirs to join their team, who recently became a paraplegic himself after a car accident. However, his bitterness over his recent accident makes this task far more difficult than they can imagine, a fact which the coach of the other team (played by Daryl "Chill" Mitchell) knows all too well.
When Zack and Cody knock the ancient mummy over the balcony, Zack dresses Cody up to replace him for the exhibit. Esteban is scared of the curse of the mummy and he puts on garlic which smells awful! He and Maddie dress up Maddie's old doll so they can give the real mummy back to its correct place, not knowing that it's Cody.
Zach and Cody take an aptitude test. Zachs score shows he will be a succesfull CEO and Cody's score shows he will be a garbage man. So Zach starts trying to study more and become a math whiz and Cody just starts to simply not care about anything. Meanwhile, Maddie gains fame after saving the Moroccan ambassadors life. This fame causes London some jealousy.