"Prehistoric" takes you on a backwards timeline to see what stood, lived, fought and died in your backyard hundreds, thousands, even millions of years ago. The high-rises and sprawl of modern Los Angeles revert to farmland and settlements, then desert. Spinning back further in time, we reveal a lush green land prowled by woolly mammoths and sabre-toothed tigers. Back even further, we see the land itself form as two continental plates, slam together in a violent upheaval. Re-winding to the age of dinosaurs, we witness pterodactyls circling the skies over an ancient ocean filled with sharp-toothed marine dinosaurs in search of their prehistoric prey.