While Scrat the Saber-toothed Squirrel is still trying to find his precious acorn, the misfit trio of Manny the Mammoth, Sid the Sloth and Diego the Sabre-tooth Tiger have settled down in an isolated valley with numerous other animals. However, the trio soon discover that the ice wall surrounding the valley is barely holding back a massive body of water behind it and the melting state threatens to break the wall and flood the valley. With their one...

Scrat's epic pursuit of the elusive acorn catapults him into the universe where he accidentally sets off a series of cosmic events that transform and threaten the Ice Age World. To save themselves, Sid, Manny, Diego, and the rest of the herd must leave their home and embark on a quest full of comedy and adventure, traveling to exotic new lands and encountering a host of colorful new characters.

When the icy continent splits in two, separating Manny from his family, he sets off with Sid and Diego to find a land bridge that will reunite them, but before long they run into a rowdy group of pirates.