Manny, Sid, Diego and Ellie are back, along with the swashbuckling one-eyed weasel Buck Wild, the mischievous possum brothers Crash and Eddie and, inevitably, Scrat, whose pursuit of his beloved acorn once again triggers chaos, this time in the shadow of an erupting volcano. Together the herd journeys into uncharted corners of the Lost World, the hidden realm of dinosaurs beneath the ice, where rising heat and fiery eruptions put everything they know in danger.