Scrat the prehistoric squirrel has been chasing that acorn for what seems like thousands of years. His quest has taken him to the top of the highest mountain, and to the depths of the deepest ocean. But when Scrat's desire for the acorn catapults him into outer space, he triggers a series of events that threaten life on Earth. Manny, Diego and Sid must now find a new place to take the herd to avoid the wrath of Scrat's misadventures. The crew travels many miles and encounters several exciting obstacles on their way towards safety.