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.

Doug and Tony are captured by the Mongols in 1287, led by Genghis Khan's grandson Baku. Tony is tortured until Doug stages a rescue, where they meet with Marco Polo, who is aiding Kublai Khan. Tony falls in love with Sahib, daughter of Kublai Khan that Polo is aiding and who is kidnapped by Baku. The guys rescue her by using black powder that Polo has discovered in China. When Baku launches an assault on the fort where Polo is staying, the Project staff try and send artillery back to the guys. They thwart an attack on the fort while Tony considers staying with Sahib. In the end she returns to her duty and the two part. Doug provides the necessary ingredient to turn the black powder into gunpowder, while the Project try and send detonator caps to assist them. With the explosives the attack is thwarted and the guys are whisked out. (Copyright 2003 Steve Crow)