When Scrat's acorn antics cause a cataclysmic crack-up, Manny (Ray Romano), Sid (John Leguizamo), and Diego (Denis Leary), go where no herd has gone before -- on a high-seas quest aboard a floating iceberg. But a menagerie of misfit pirates are determined to shiver their troubles and capsize their journey home.

When a new threat emerges that puts both Bird and Pig Island in danger, Red, Chuck, Bomb, and Mighty Eagle recruit Chuck's sister Silver and team up with pigs Leonard, his assistant Courtney, and techpig Garry to forge an unsteady truce and form an unlikely superteam to save their homes.