Mettalus is flying an ice-pick shaped rocketship, and calls Ghost Planet. Space Ghost answers, and Mettalus invites Space Ghost over to Mettalus' space armada to save the universe. Space Ghost leaves Jan and Jace without a babysitter to try and figure out what evil Mettalus is brewing.
Space Ghost flies in Mettalus' ship and asks what Mettalus is going to do. It turns out Mettalus just wants to show off his two missile-shaped robots. A green one is good at outthinking tracking devices and a blue one can destroy missiles. Mettalus shoots off his two robots, and the blue one kills the green one in a kamikaze bombing. Mettalus gloats, because apparently this was supposed to happen. Mettalus explains that he has thousands of these robots, and is going to shoot them all off in an hour, before throwing Space Ghost off the ship.
Later, Jace, Jan, and Space Ghost are flying in a spaceship. Jace and Jan are confused why Mettalus would show off his evil plan and then let Space Ghost go. Space Ghost decides to attack Mettalus, ejecting from the spaceship. Both Space Ghost and the spaceship (as well as the kids) turn invisible.
On Mettalus' spaceship, Mettalus is gloating how he's confused Space Ghost, and reveals that his radar can track invisible Space Ghost. Mettalus, being the prepared blighter he is, has invisible robots fly off to attack Space Ghost.
Space Ghost also has radar that can track invisible things, and dodges the invisible robots, which he then destroys with arm-lasers.
Mettalus, realizing his invisible robots failed to kill Space Ghost, sends some heat-seeking robots after him.
Jace decides that they should stay invisible, but go help Space Ghost.
Space Ghost notices the heat-seeking missile-shaped robots, and blows them up.
Jace and Jan, still being invisible, sneak onto Mettalus' ship and into his missile-robots' armory. Mettalus arrives, explaining he can detect invisible things with his radar. Mettalus decides to shoot off a bunch of missiles at Space Ghost. Jan notices some sort of anti-robot gun and decides to use it on Mettalus. Mettalus is frozen. Space Ghost arrives, tearing a hole through Mettalus' ship. Jace gives Jan the credit for defeating Mettalus. Space Ghost decides to leave Mettalus, assuming that someone will eventually come to arrest him.
Jace asks why Mettalus is still trying to destroy the universe. Space Ghost decides that he doesn't know.