When Theodore gets to pick the show to watch, his bear recommends Talking Teddy TV Fun Time. Unable to stand anymore of the bear, Alvin convinces Simon do something about it. Simon comes up with the idea to rewire the bear so they can control what it says. The next night Theodore seems a little upset by the change of his teddy. While Alvin starts to abuse his control on the bear, Simon tries to dampen Alvin's actions. After Simon wants to end the charade, Alvin steals the keyboard, hides, and continues to take advantage of Theodore, to Simon's displeasure. Simon, unable to take anymore, rewires the bear once more so he can use Teddy to teach Alvin a lesson. Once he succeeds in freaking out Alvin, Simon convinces Theodore to donate Teddy to a daycare program. Theodore returns with a new and improved Talking Teddy.
Alvin is not thrilled about going back to school until he sees the new Principal and takes interest in her. At the bell of his first class, Alvin rushes to the Principal's Office where he discovers Brittany is her assistant. Brittany refuses him admittance until he is sent for back-talking to his teacher. Alvin treats her to a long-winded story that concludes with him kissing her hand. After misbehaving in class over and over again, the Principal talks to Dave which Alvin interprets as competition. To prevent him from seeing the Principal, his teacher states a new rule in which he won't see her anymore. His continued misbehavior ultimately leads to his suspension. Dave, unable to stand Alvin and unaware he followed him, meets the Principal at a cafe. Alvin crashes the dinner and learns she's married.
After Alvin annoys his teacher enough so he can get out of detention early, he sees Brittany go into the school's basement. When he takes a peak, he sees a green light and is convinced an alien is inside. At home he tells Simon who doesn't believe a word of it. The next day Alvin confronts Brittany, who spills nothing, and rushes back to the basement at the end of class only to find a neon-green substance on the floor. Simon analyses it and determines it's silicon-based. Despite Simon's request that he drop the matter, Alvin wakes Simon up and forces him to go back to school where they are caught snooping by a security guard. They run home to find Theodore missing so Simon reveals his secret jet packs. Back at school, they see a UFO which, in reality, is part of a movie set they crash onto landing them in detention.
The Chipmunks surprise Jeanette for her birthday, but she doesn't want to celebrate because the world is less than magical. Brittany isn't happy so she comes up with the idea to rig their treehouse with holograms and strings to give her sister magical powers. The next day, Theodore decides to extend her magical powers by giving her a hat of invisibility. Even though upset by Theodore's decision, they are forced to continue the charade once Alvin's present arrives late (an owl with an acceptance letter to Wizard School) and Jeanette casts more spells. When Theodore takes Jeanette to see her favorite movie, Simon paints the next door house, Alvin looks for the neighbor's dog, Eleanor cooks, and Brittany replaces flowers. At dinner Alvin confesses everything. Alone, Jeanette ponders their actions and thanks them for making her life magical.
When Dave gets a parenting app to help supervise The Chipmunks, Alvin tries everything to escape its control.
Alvin, Simon and the Chipettes give Theodore conflicting dating tips when they believe he has a crush on a girl. Will our little Romeo be able to make sense of all this?
When Alvin catches Simon taking a personality test to discover his soul-mate, he decides to do the same and prove just how silly the test really is. But when the test reveals that his own soul-mate is...Brittany, Alvin decides to do something dramatic and becomes a bow tie wearing preppy!
Tired of Bocarter Humphrey, the class president, favoring his personal pals, Simon and Alvin decide to rebel and launch their own campaigns for class president. Will brotherhood survive the competition?
Simon is ecstatic when he's elected as the school's safety monitor and gets to choose the destination of the upcoming family vacation. But when Alvin goofs off at school, Simon faces a moral dilemma, and has to choose between doing the right thing or giving Alvin detention and ruining the family vacation.
Fed up with seeing how dependent The Chipmunks have become on their technology, Dave decides to take them camping for a weekend, without electricity, cell service or the Internet. But what seems like a good idea turns into a nightmare for Dave and our boys.
Theodore is desperate to land the part of the monster in the school play, so Alvin decides to show Theodore how to really scare people. But Alvin scares him so badly, that poor Theodore freezes like a statue. Can Alvin and Simon unfreeze Theodore before the big audition?
When an accident forces Simon to wear his embarrassing old glasses, he becomes the target of the school bully. Unwilling to remain a victim, Simon builds a homemade robot bodyguard that helps Simon stand up to the bullies.
Jeanette wants to give a toast to Brittany at her upcoming party. But Jeanette is so shy, she seeks advice from the most confident person she knows...ALVIN. But his advice embarrasses Brittany to the point where she decides not to invite Jeanette to her party.
Needing to find a part time job in order to buy the latest video game, Alvin decides to "borrow" Brittany's baby-sitting job. But Basil, a sensitive little six year old boy, is not too thrilled at having Alvin look after him. So he decides to put Alvin through the wringer!
Theodore is convinced that Miss Croner's missing cat is the cause of a terrible curse. And the only way to break the curse is to find Mister Whiskers.
When Dave comes down with a bad cold, Alvin quickly offers to take over Dad duty. But he quickly learns that parenting is a lot harder than he ever imagined.
Dave is concerned that The Chipmunks have become too obsessed with their latest video game. But when they challenge Dave to play the game before judging it, Dave becomes even more addicted than The Chipmunks.
Grounded once again, Alvin begs Theodore to buy him the limited edition skateboard he's always wanted. But, Theodore gets sidetracked by his sweet tooth and squanders all of Alvin’s money on candy instead. Now Theodore is forced to tell the truth or make up an improbable story.
In a rare moment of generosity, Alvin gives his beloved cap to a fan. But soon he's convinced his mojo was in his cap, and must find a way to get his hat back before the Chipmunks' big concert.
During a costume visit to the zoo, Alvin finds himself mistaken for a real Tasmanian devil. Soon, Alvin is stuck in the Tasmanian devil's cage and the real animal, goes home to the Sevilles'. The mix-up creates problems all around, especially when Simon reads that the Tasmanian devil is scheduled for surgery. Can Dave and the boys get to Alvin before the operation?
