Sent back 40,000 years to the ends of the last great Ice Age, the time travelers embark on a journey of survival and discovery. The brutal and cannibalistic Cro-Magnons discover the small band and attack. Forced to flee from their high mountain encampment, the tribe heads into the dawn, towards the Pacific Ocean and their dream of ultimately reaching North America. Geena and Micah are left behind to lead the Cros away from the escaping tribe. When he is killed, she finds herself terribly alone. Severely injured and without hope or resources, she nonetheless is determined to survive and find the people. Survival of the fittest - that is the law of primordial Earth.