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...