When three children find an egg-shaped time machine, their curiosity gets the better of them. They accidentally turn the contraption on and find themselves millions of years in the past. What's more, they've landed right in the middle of a dinosaur's nest of eggs, and the mother T-Rex is right there staring at them. Fortunately for the children, she thinks they're family, not food. However, they only have until the real eggs hatch to find a way back to their own time.