Professor Mortimer is bequeathed an old house in France by a former adversary: Miloch, the evil genius of SOS Meteors fame. Along with the house is a letter inviting the Briton, as the only man of worthy intellect, to discover a fabulous invention left behind by the departed. Following recorded instructions, Mortimer activates the device – and wakes up a hundred million years in the past! Thus begins an incredible odyssey through time!