There was a time when just the whisper of the name "Jack the Ripper" struck terror into the hearts of the brave. It was autumn, the fall of 1888, and an evil monster, responsible for committing a series of gruesome murders, was stalking the streets of London. The crimes have never been solved to this day and the story of "Jack the Ripper" is still the stuff of nightmare.
When a virus leaks from a top-secret facility, turning all resident researchers into ravenous zombies and their lab animals into mutated hounds from hell, the government sends in an elite military task force to contain the outbreak.
With the impending ice age almost upon them, a mismatched trio of prehistoric critters -- Manny the woolly mammoth, Diego the saber-toothed tiger and Sid the giant sloth -- find an orphaned infant and decide to return it to its human parents.