The guys arrive in Arizona, 1547, as a technician named Niman kills a scientist. After a shootout, he flees into the Tunnel. Niman is a spy who has planted a nuclear device in the complex. The guys need to find Niman to get him to reveal the location of the bomb. They lure him in with a fire but he slips, and the Project transfer Doug and Tony after him to 1,000,000 A.D. Niman is already there and has established himself with the ruling clique. The guys get the info on the detonation time, bypass a force field, and with the aid of a local female "defective" manage to get to Niman. The Project transfers everyone, including two of the future-types, back to 1,000,000 B.C. After some running around from dinosaurs, they rescue Niman from a quicksand pit in return for the location of the bomb. The head alien eventually comes around and forces Niman to give the location of the bomb which they defuse. Everyone ends up in a giant bee hive and the Project gets everyone but Niman out.