Twenty thousand years ago glaciers were over-running the Earth & creatures everywhere were fleeing the onslaught of the new Ice Age. In this time of peril we meet the weirdest herd of any age: a fast-talking but dim sloth named Sid; a moody woolly mammoth named Manny; a devilish sabre-toothed tiger named Diego; & an acorn-crazy sabre-toothed squirrel known as Scrat. This quartet of misfits unexpectedly & reluctantly come together in a quest to return a human infant to his father. Braving boiling lava pits treacherous ice caves freezing temperatures & a secret evil plot they become the worlds first heroes!