It's been four years since we last saw the characters from Ice Age. The ice age is in full swing and the mixed race herd has settled into their new lives. All seems to be going fine and everyone is happy. But along comes a fast talking lizard crying, “Doomsday!” Of course, after the standard misunderstandings, Manny the mammoth finds the threat to be real. Now, along with Diego the saber tooth tiger and Sid the sloth, they must lead the herd to safety at the far end of the valley.
There you have the story upon which are hung many gags and side stories that comprise the movie that is Ice Age: The Meltdown. I hate to say it, but the story felt very tired and drawn out. I didn't find myself connecting with the characters on any level. I'd be lying if I said I wasn't entertained, I was. However, I wasn't captivated by the story. I didn't really buy into the whole flood thing. Sure, I know it's an animated film targeted primarily at kids, but is it too much to ask to have a story that is at least interesting?
Besides the flood and leading the herd out of danger, which seems to be pushed to the side shortly after the initial move, the main characters get their own side stories. The biggest side story would have to be Manny's. Throughout, he is struggling with the possibility that he is the last of the mammoths; that is, until they meet up with Ellie, a mammoth who thinks she is a possum. This leads to much comedy. There is also a thread concerning Diego and his fear of water, which never really takes off. Finally there is Sid, constantly trying to prove himself a worthy part of the herd. Sid also gets to feel the pressure of being at the head of a herd, a pressure he really doesn't want.