Manny, Sid, and Diego are currently living in a large valley surrounded by an enormously high ice wall on all sides. However, the trio discovers that the ice wall is actually a dam that is barely holding a massive body of water that could flood the valley to nearly a mile underwater. A vulture tells them that there is a boat at the other end of the valley that may save them all, but they only have three days to reach it or die. Manny is also having trouble fearing the fact that he may be the last mammoth left.