Quick recap
The herd lives in a valley ringed by an ice wall that's really a dam about to burst. A vulture says there's a boat at the far end, three days away. On the way, Manny, Sid and Diego meet Ellie, a mammoth raised by possums who thinks she is one, and her brothers Crash and Eddie. Two thawed sea reptiles also hunt the group. Manny, who thinks he's the last mammoth, falls for Ellie. When the dam fails, Manny saves her, and Scrat cracks open the ice, draining the flood and revealing more mammoths. Manny chooses to stay with Ellie.

