A time traveling scientist goes back to prehistoric times and feeds dinosaurs a magic cereal that increases their intelligence - next they land in modern New York City for a series of comic adventures.

A mysterious object crashes near the great valley, and Petrie's untrustful uncle arrives in search of it, believing it to be "a storm of cold fire", a susposed rock of great powers.

After his father doesn't return from an important journey, Littlefoot and company set out to find him.