Alvin and the Chipmunks: The Squeakquel is an American live-action/CGI film and sequel to Alvin and the Chipmunks. During the Chipmunks' benefit concert in Paris, France, David Seville (Jason Lee) suffers a severe injury and is rushed to the hospital.
Although he survives, he must stay for a few days to recuperate, so he leaves his cousin Toby (Zachary Levi) in charge of the Chipmunks until he returns.
Prior to the event, Dave had made arrangements for Alvin (Justin Long), Simon (Matthew Gray Gubler), and Theodore (Jesse McCartney) to attend school. Little does he know, on their very first day, the Chipmunks feel like "Chipmunks Out of Water" on account of all the human students around.
Meanwhile, Ian Hawke (David Cross) (after the departure of the Chipmunks dealt him a serious blow) searches the world for animals who can sing and dance.
He happens upon Brittany (Christina Applegate), Jeanette (Anna Faris), and Eleanor (Amy Poehler), the Chipettes, and cannot wait to make them famous, and get his sworn revenge on the Chipmunks. Although the Chipettes accept, they do not know that Ian has no job.