At the dawn of the great ice age, a group of three animals embark upon an epic journey. Sid the sloth, Manfred the mammal, and Diego the sabre-toothed tiger team up to help return a human baby to its father, and must risk life and limb as they traverse boiling lava pits and travel through dangerous ice caves to complete their mission. Along the way they also meet Scrat, a squirrel-rat determined to plant an acorn in a glacier. Features the voices of John Leguizamo, Denis Leary and Jack Black.