Jeff leaps to safety just before the truck crashes. He returns to the cave with the pseudo Rocket Man who turns out to be Millard. The professor demonstrates the powerful Decimator. Later, feeling his moves are being watched by Vulcan, Rocket Man sends Glenda and Burt to the cave with the Decimator and radios Millard to this effect. His message is intercepted by Vulcan who effects an attack on Jeff and sends his men to the cave to imprison Burt and Glenda and to fetch Millard and the Decimator. Jeff escapes and flies as Rocket Man to the cave. A fight starts with Dirken during which the Decimater is accidentally turned on, its force unleashing a lava flow through the tunnels. Rocket Man, Burt and Glenda soon find all escape cut off by the oncoming molten lava which overtakes them in one of the tunnel passages.
