During China's Tang dynasty the emperor has taken the princess of a neighboring province as wife. She has borne him two sons and raised his eldest. Now his control over his dominion is complete, including the royal family itself.
Manny, Sid, and Diego discover that the ice age is coming to an end, and join everybody for a journey to higher ground. On the trip, they discover that Manny, in fact, is not the last of the woolly mammoths.