Their former foe, the Sizzler, has become something of an adopted mascot for the Metal Men. Unfortunately, the Sizzler has also transformed the Metal Men's creator, Doctor Will Magnus, into a robot, with seemingly no intention of reversing his transformation. The Sizzler's creator, Professor Snakelocks, observes the Metal Men, from high in the sky, piloting a glider. As a show of good faith, the Sizzler brings Professor Snakelocks' plane down, and turns her inventor over to Magnus. Pressing a button on his lapel, Professor Snakelocks summons a small army of robot toy soldiers, which expand on contact with the air, from his glider. Lead quickly forms a shield to protect his allies from the assault. Platinum then draws herself out into barbed wire, and ensnares the toy soldiers. Professor Snakelocks launches a wave of shells, that rain down on the Metal Men.

Tin molds himself into an umbrella to shield the team, buy proves too fragile. Ultimately, it is Iron who saves the Metal Men from the missile attack. When Professor Snakelocks warns Magnus not to trust the Sizzler, Professor Snakelocks, too, is transformed into a robot, by his renegade creation. As no court will prosecute a machine, Magnus decides to incarcerate Professor Snakelocks in the library, until the Sizzler can be convinced to reverse the transformation. With Professor Snakelocks long out of communication with his superiors, the Lizard is enlisted to complete Professor Snakelocks' mission, to destroy the Metal Men. When Magnus, once again, spurns Platinum's amorous advances towards him, while showing favoritism towards the Sizzler, Platinum quits the Metal Men. Outside their headquarters, Platinum is taken prisoner by the Lizard.

Platinum is forced to write the ransom demand for her safe return. Each Metal Man is to take a sum of money to a different location. In this way, the Lizard can pick them off one by one. Iron is the first to encounter the Lizard's forces. Despite the trap springing flawlessly, Iron proves a more intractable foe than the Lizard anticipated. Gold, too, proves more resourceful than expected, and also gains the upper hand on his attackers. Lead, too, is able to defeat his attackers quite easily. Mercury, however, runs into trouble, when the Lizard's men throw the Mercurial Metal into an aquarium tank holding a swordfish. By separating into individual globules, Mercury is able to escape from harm. By the time he extricates himself from the tank, though, the Lizard's men have fled, with the ransom money. By working together, Tin and Nameless triumph over their attackers.

Magnus has been instructed to bring the ransom money to Platinum's actual location. There the Lizard's men prepare to ambush Magnus. Platinum sacrifices herself for Magnus, allowing her creator the chance to bring down the Lizard, and his few remaining men. Back at his laboratory, Magnus rebuilds Platinum. Misunderstanding Magnus' attentions towards Platinum during her reconstruction, the Sizzler jealously lashes out at Magnus. The Sizzler's radiation bombardment transforms Magnus back into a human being. Magnus gets the Sizzler to transform Professor Snakelocks back into a human, as well, at which point he is turned over to the proper authorities. Now with both the Sizzler and Platinum jealously competing for Magnus' attention, the famed inventor fears he will no longer be able to get any work done.