The sub-zero heroes from the worldwide blockbusters "Ice Age" and "Ice Age: The Meltdown" are back, on an incredible adventure...for the ages. Scrat is still trying to nab the ever-elusive nut (while, maybe, finding true love); Manny and Ellie await the birth of their mini-mammoth; Diego the Sabre-toothed tiger wonders if he's growing too "soft" hanging with his pals, and Sid the sloth gets into trouble when he creates his own makeshift family by hijacking some dinosaur eggs.