A wild ride on a merry-go-round sends the Chipmunks back to 1962. They meet a younger Dave. Without the boys' help in winning a band contest, he will spend his life as an accountant. When they are spun into the present, Alvin isn't sure whether he visited the past or bumped his head in a fall off the merry-go-round.

Alvin "borrows" Dave's new bike, and while he is out riding he accidentally hits Brittany who is out roller skating. The bike is ruined, and something is wrong with her skates. They each blame each other, and Alvin demands Brittany pay for Dave's bike, while she insists he pay for her roller skates. All of this brings us to court, where Brittany and Alvin, ignoring the "TRUTH" part in justice, face off in a "who can tell a better lie about what happened" court battle.

Theodore goes on a diet so he could go on a date with a pen pal, who is also one of Alvin's biggest fans. Things go wrong when Alvin finds out that Theodore's date is actually the daughter of a famous film director. Alvin then takes her out instead, breaking Theodore's heart. In order for Alvin to make it to his play and the date, Alvin gets Theodore to switch back and forth to his play and on his date.

Brittany makes a bet with Missy Snootson, another girl in her class, that if the mummy of king Rooten Tooten does not rise from the dead and go to her home by midnight, Brittany must drop out of the race to be the school Carnival Queen.

While Dave is out of town, Miss Miller babysits the boys and they go to a movie about killer space squids attacking the earth. Accidentally miss Miller breaks Simon's glasses. When they get out a telescope that evening, Simon thinks he sees killer squids coming toward earth, just like in the movie.

The boys have to paint the garage after they got spray paint on the walls while repainting their bicycles. Simon and Theodore feels bad because they always have problems with Alvin's ideas. Later Alvin have them to go to a mansion of a now dead criminal. Alvin is convinced that a never found loot from a bankrobbery is still hidden there. They go because Alvin promises to paint all the garage if he's wrong, but they feel a little bad with Alvin.

Alvin goes through an identity crisis and starts trying all kinds of different personalities, with embarrassing results.

After years of scrimping and saving, Dave is finally able to afford their own vacation cabin. Alvin hears that Robby Leach, the host of the show “Lifestyles of the Truly Fabulous” lives nearby. Alvin tries to get Leach to interview him, and at the same time he makes a few quick changes to Dave's cabin.

Alvin nearly runs over an elderly woman in the mall with his skateboard. When Alvin finds out that she is wealthy, he sends out invitations for a senior citizens' party in order to find her.

While in England, the Chipmunks check out Seville Manor to investigate if they have any relation to the man who owned it.

The family becomes fed up with Alvin, who always gives out advice whether it is wanted or not. So Simon and Theodore get Alvin to become the new host on the talk show “Mr. Advice” so he will not have time to badger them.

Theodore is feeling unlucky in the track and field. He finds a bent out of shape dime and his luck changes.

Alvin gets a registered letter from the Publishing Warehouse stating he's a winner! He either could take $500 or the mystery prize, but had to call by 6:00 pm to decide.

The Chipmunks and Chipettes get to perform on a high class cruise ship, the Island Lady, but instead they end up ship wrecked on an island.

Miss Miller & the Chipettes are vacationing in Hollywood, as well as Miss Miller reuniting with her girl singing group, The Thrillers.

The Chipettes get an opportunity to star on the River Ritz Hotel in New Orleans, Louisiana.