When their beloved guardian Jason Lee embarks on a trip to Miami with his new girlfriend, the rambunctious Chipmunks—Alvin, Simon, and Theodore—stumble upon a plan that sends them into a panic: a potential marriage and a new baby brother. Fearing they’ll be replaced and sent packing, the musical trio, voiced by Justin Long, Matthew Gray Gubler, and Jesse McCartney, hatch a desperate scheme to derail the proposal. This leads them on a chaotic, cross-country race from Los Angeles to Miami, with their mischievous antics putting them on a collision course with a vengeful air marshal, played by Tony Hale. Directed by Walt Becker, this family comedy is a whirlwind of musical mayhem and madcap adventure as the boys, joined by the Chipettes, navigate airports, alligators, and the deep bonds of family, all while trying to prove that home is where the heart—and the loudest singing—truly is.