After the events of "Ice Age: The Meltdown", life begins to change for Manny and his friends: Scrat is still on the hunt to hold onto his beloved acorn, while finding a possible romance in a female sabre-toothed squirrel named Scratte. Manny and Ellie, having since become an item, are expecting a baby, which leaves Manny anxious to ensure that everything is perfect for when his baby arrives. Diego is fed up with being treated like a house-cat and ponders the notion that he is becoming too laid-back. Sid begins to wish for a family of his own, and so steals some dinosaur eggs which leads to Sid ending up in a strange underground world where his herd must rescue him, while dodging dinosaurs and facing danger left and right, and meeting up with a one-eyed weasel known as Buck who hunts dinosaurs intently.

1914: Milo Thatch, grandson of the great Thaddeus Thatch works in the boiler room of a museum. He knows that Atlantis was real, and he can get there if he has the mysterious Shephards journal, which can guide him to Atlantis. But he needs someone to fund a voyage. His employer thinks he's dotty, and refuses to fund any crazy idea. He returns home to his apartment and finds a woman there. She takes him to Preston B. Whitmore, an old friend of his Grandfathers. He gives him the shepherds journal, a submarine and a 5 star crew. They travel through the Atlantic ocean, face a large lobster called the Leviathan, and finally get to Atlantis. But does the Atlantis crew have a lust for discovery, or something else?

This story follows a teenage rock hopper penguin named Cody Maverick from his hometown of Shiverpool, Antarctica, where all of the other penguins think he's nothing but a surfing fool, to the "Big Z Memorial Surf Off" on Pen Gu Island. Young Cody is determined to win the most important competition in the world of penguin surfing in honor of "Big Z," a deceased surfing legend whom he has idolized since childhood. But the waves in Pen Gu are different than in Shiverpool, and the competition is steep. The current champ, egotistical Tank Evans, isn't just about to let this little penguin knock him from first place without a fight. When Cody wipes out and encounters Geek, a recluse aging former surfer, living in the jungle, he learns some important lessons about life and surfing, and even teaches Geek a thing or two.

Manny the woolly mammoth, Sid the sloth, Diego the saber-toothed tiger, and the hapless prehistoric squirrel/rat known as Scrat are still together and enjoying the perks of their now melting world. Manny may be ready to start a family, but nobody has seen another mammoth for a long time; Manny thinks he may be the last one. That is, until he miraculously finds Ellie, the only female mammoth left in the world. Their only problems: They can't stand each other--and Ellie somehow thinks she's a possum! Ellie comes with some excess baggage in the form of her two possum "brothers"-- Crash and Eddie, a couple of daredevil pranksters and cocky, loud-mouthed troublemakers. Manny, Sid and Diego quickly learn that the warming climate has one major drawback: A huge glacial dam holding off oceans of water is about to break, threatening the entire valley. The only chance of survival lies at the other end of the valley. So our three heroes, along with Ellie, Crash and Eddie, form the most unlikely family--in any "Age"-- as they embark on a mission across an ever-changing, increasingly dangerous landscape towards their salvation.