Ice Age: The Meltdown is a 2006 American computer-animated comedy adventure film produced by Blue Sky Studios and distributed by 20th Century Fox. As the first sequel to the 2002 film Ice Age, it focuses on The Herd escaping an upcoming flood, during which Manny finds love.
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.
During the evacuation, a glacier that contains two sea reptiles from the Mesozoic era, Cretaceous a Cymbospondylus and Maelstrom a Pliosauroidea, breaks off. When Manny is briefly separated from them, Diego and Sid encounter two mischievous opossums named Crash and Eddie who drive them nuts by playing Whac-A-Mole with them. Manny is still worried about being the last mammoth alive and his family, who had been killed by humans, but is surprised when he encounters Ellie, a female woolly mammoth who believes she is an opossum and Crash and Eddie’s adoptive sister. Sid invites her to tag along with the group to escape the flood, and she brings her brothers. After a dangerous encounter with Cretaceous and Maelstrom while crossing a pond, Sid prompts Diego to encourage him to admit and face his fears – Diego insists that “fear is for prey”, so Sid points out that Diego is behaving as if he is the water’s prey. They discover an area which Ellie recalls as the place where she was adopted. She finally realizes she is a mammoth and also expresses her suspicions about how different she was from other opossums. Despite this bonding moment with Manny, she distances herself from him when he suggests “saving their species”. Ellie and Manny ultimately make up when they must co-operate to save the group when the ground cracks under their feet. Sid is kidnapped by a tribe of mini-sloths who believe Sid to be a god. Sid lights a fire for them, and believes that he has finally found respect, but they plan to sacrifice him by tossing him into a volcano; Sid narrowly escapes. The next morning, Sid tells the others his experience but none are convinced. After being harassed by vultures, the group finds the boat behind a field of hot geysers, which separates Manny, Sid and Diego from Ellie and her brothers when they argue about which way’s safest to go through.
When the flood comes, Manny saves Ellie from drowning as she is caught in a cave (due to falling rocks), while Diego overcomes his fear of water to save Sid, Crash and Eddie from drowning. Cretaceous and Maelstrom arrive, but due to Manny’s quick thinking, they are finished off by a rock which falls on them, killing them both. The other animals are at the mercy of the water currents. Meanwhile, Scrat climbs up the glacier and at the top sticks the acorn he has into the ice. This forms a crack in the glacier, which widens into a fissure, diverting the flood and saving the animals in the valley; Scrat is then washed away. In the final scene, a herd of mammoths show up, proving mammoths aren’t extinct. But Manny and Ellie decide to remain together anyway, taking Sid, Diego and the opossum brothers along. Sid encounters the mini-sloths again – they believe Sid stopped the flood and invite him to be their leader. Diego, surprised to see the mini-sloths are real, convinces Sid to stay with the others, admitting that Sid is a vital part of their ‘herd’.
The epilogue shows Scrat having a near death experience after falling into the fissure. He enters a heaven full of acorns. Suddenly, he finds himself torn away. He unhappily wakes up, having been resuscitated by Sid, who he proceeds to viciously attack.