Giant metal robots appear out of nowhere and start destroying everything. When Cave Carson and his team are using the Mole's Thermo-Ray to stop one of the giants but the robot's metal appears to be unbreakable. In return, the robot attacks the Mole and the team decides to hide into the ground where they discover the underground base of the aliens who control the robots...
- The Alien Robots from Inner Space
- The Battle of the Giant Robots
- Subterranean Showdown