It's the first day of summer, and London goes to Maddie telling her that she likes summer vacation because she doesn't like being stuck in a school all day. Maddie replies that some people actually go back to school after they have lunch. London explains that she's spending the summer on her yacht, and Maddie explains that she gets to help her mom do a certain chore, that London finds pretty nauseating.
Sister Dominick comes to The Tipton Hotel, saying that she needs camp counselors for "Camp Heaven on Earth". She originally asked London, but she said she's doing nothing for a summer job but Maddie willingly accepts.
A few hours later at school, Zack and Cody's teacher announces the year's valedictorian. Barbara and Cody getting into a heated debate about who it's going to be, Cody votes its going to be Barbara considering she got A+ in every subject (according to Cody that includes dimples), but they agree that the winner kisses the loser. And Cody is valedictorian, and he tries to get Barbara to kiss him, but instead she steps on his foot. But their teacher pulls Zack aside saying that he failed English, and he can't graduate unless he attends (Su...Su...Su...mer School), but his teacher pats him on the back and tries to get him to feel better.
Meanwhile at camp, Maddie finds out that "Camp Heaven on Earth" is nothing like the picture (it was taken in 1929, BEFORE the locus blight), Maddie feels quite unsafe there. Plus she has to take care of four young con-artists Amy, Jasmine, Leah, and Holly the same con-artist in "Have a Nice Trip", Maddie spots Holly and sues her, but Holly defends herself saying she won fair and square. She then shows her all her watches. Maddie tells Sister Dominick that Holly is a criminal, then Sister Dominick says they banned the word "criminal", and that the four girls she has to take care of have had misfortunate moments, but they are as sweet as daffodils. Sister Dominick checks the girls' pockets, and they're clean. Maddie tells the girls she brought each a small gift, when she notices her backpack is missing. Holly tells Maddie Amy took it, Amy denies it, when some ham falls out of her bag. She explains her toy Mr. Hammy, that was given to her by her ex-boyfriend. Jasmine tells her that Amy also is a liar, but Amy fights back saying she doesn't have anger issues like Jasmine. Jasmine attempts to shove Mr. Hammy up Amy's nose, but Maddie really wants to find out anything she needs to know about Leah. Which is that she doesn't talk, Maddie whispers that so far Leah's her favorite.
Cody tells Zack their mom is going to be mad, if she finds out that Zack isn't graduating, but Zack decides to let Cody choke on his apple. Zack decides that he must tell Carey, but first pretend to be crying, and then they get inside their room. Carey tells them shes baking cake for a special graduation party. Which she failed to bake it the first time. Zack pretends to cry, and Zack decides to tell her what happened. Unfortunately, while telling her, their dad, Kurt shows up, saying that he took time from his tour to watch the boys graduate. Zack lies, saying that he graduated, and Kurt says he won't miss the boys getting their diplomas, the cake falls onto Zack, when Cody takes a lick.
The next day, Maddie tells the girls that they are going to make curtains, but Leah, Amy, Jasmine, and Holly decide to give her a gift to say "welcome", it turns out to be a rubber raccoon, which Maddie totally finds unamusing. Leah says shes laughing, which Amy is shocked to know that she "talked", and then as she starts to sing if you're happy and you know it, they don't clap until she yells at them, too.
London gives Mr. Moseby, the options of which island, yacht, and bathing suit he liked better. But Mr. Moseby refuses to answer, but right about then London gets a telephone call from Maddie, she's saying that the girls are vicious monsters, and that London has to go to Camp Heaven on Earth to pick her up. London tells her that she'll save her as soon as she gets the Tipton Helicopter later. Mr. Moseby tells London that he's lad she's missing a massage in order to help a friend. London remembers her shiatsu, and thinks Maddie can wait a bit.
Zack sneaks into the graduation, Cody tells him that its only for the people in the 8th grade that are graduating. Zack gets a plan to steal someone diploma, realizing that they are only enough gowns and diplomas for the people graduating. Cody sarcastically tells Zack about forging a diploma and stealing a gown. Zack kisses Cody, and does this and becomes part of the graduation. Barbara goes to Cody and tells her that she's sorry she got angry, because she creamed him in the math competition, and Cody annihilated Barbara in the spelling bee, but Barbara gets mad again but Cody tells Barbara her dog is not smart, but Barbara stomps on his foot once more.
Meanwhile, at Camp Heaven on Earth, Maddie gets frightened during a storm, when London comes to the door to rescue her. Maddie asks London if the rain slowed her down, but London says she had 20 minutes of her massage. Maddie gets angry at her, but London tells her she has the helicopter, she packs her suitcase but hear the girls singing "If you're happy and you know it clap your hands", Maddie jumps onto London, and she holds her. Holly and London get to know each other. Holly compliments on London's diamond bracelet, and asks her to play a game of cards, but Maddie tells her not to do it, and pulls London outside, but London doesn't believe Maddie is afraid of the girls (except for Leah), Maddie and London try to escape towards the helicopter, but before they can it gets decimated by a large tree.
Zack calls his teacher telling him about his mom's car being in the Charles River, he rushes to the rescue. The boys walk up the stage as Kurt and Carey take pictures of the two boys. Cody gives his speech as the valedictorian. Carey and Kurt take another picture When the diplomas are being handed out, after Cody gets called up to get his diploma, Zack throws a spitball at the lady up on stage, causing her to shout out his name. Zack pretends to get a diploma and he successfully fools Kurt and Carey by stealing a diploma.
Back at camp, Maddie is worried that she and London are never going to escape Camp Heaven on Earth, London tells her not to fear because her other helicopter, she has on her beach house in Newport is on her way to rescue them both. Jasmine says London is pretty lucky, considering she lives with five brothers, and they share ONE TOOTHBRUSH! Leah says to brush her teeth she uses her grandmother's finger. Holly tells her for relatives, she has neighbors, while her Dad is out working. Amy tells the gang that for neighbors, she has wolves that never share meat with her. Sister Dominick comes inside to ask why a crushed helicopter was by the tree, London says it was hers, and that it was coming to take Maddie home, Sister Dominick tells the gang to pack their bags only with items that belong to them, Holly says she's going to miss sleeping in her own bunk.
Amy tells the girls that she has the cave floor, when Jasmine, Leah, and Holly tell her to be quiet. London tells Maddie that her helicopter is here and that now they can escape, but Maddie looks at the girls' sad faces, and Maddie tells the girls that they need to treat her with respect if they want her to stay, and they promise. So Maddie agrees to stay with the girls, but London leaves to get inside the helicopter. Right when Maddie is about to get on her bed it falls apart, and Holly agrees to start then.
At the graduation party that Carey planned in their suite, Barbara apologizes to Cody once more, but when Cody tells Barbara that when he goes to high school he's taking more AP classes than she is, Barbara stomps on his foot but lets out a scream, and Cody brags to her about his steel-toed boots. Mr. Moseby asks to propose a little toast, he gives Zack and Cody a little gift, but then he says he hopes the boys find out they're days of running in the lobby are over, and that they are that much closer to becoming adults. Kurt gives Cody an abacus, but Zack makes fun of him, then Kurt gives Zack his favorite guitar as a present, and Mr. Moseby starts to cry because he sees its beautiful that the boys are moving on to high school Carey and Kurt brag about Zack graduating. Zack feels guilty, and tells them that he didn't graduate. Mr. Moseby takes back the gift that he got Zack, Zack admits he faked the whole thing. But Carey takes out his diploma and it has a girl with a picture of a girl wearing a bikini. Kurt thinks she's hot, but Carey isn't amused, and asks Zack why he did it, and he tells him everything. Kurt and Carey are disappointed that he didn't graduate but even more disappointed that he didn't be honest instead of lie. Then he says he just needs to pass summer school.
As a result, Zack must give back Kurt's vintage guitar that Kurt gave to him. Carey gives them a cake that's store-bought, Kurt tries to look at the girl wearing a bikini, but Carey tells him to put it down.