The Rulons attack the Dino-Riders' camp just as they manage to successfully reactivate the S.T.E.P. on its new command center. When the victory is about to go to the Rulons, Astra and the commandos transport the S.T.E.P. to the safety of another time. But a miscalculation brings them to the Ice Age and in the middle of a war between some peaceful Cro-Magnons and a greedy tribe of Neanderthals. The commandos now have two missions: help their new allies defeat their enemies, and devise a plan to beat back Krulos's latest attack.