The Metal Men are locked in a vault. Suddenly, laser fire begins penetrating the vault door. The Metal Men mold themselves into an oversized vise to smash the door open. In the outside corridor, four men with laser weapons fire upon the Metal Men. The Metal Men are quick to put their assailants down. With their captives in tow, the Metal Men seek out the military base's commanding officer, Colonel Craven. The Colonel is in conference with the Metal Men's creator, Doctor Will Magnus. The Metal Men deliver their prisoners to Craven, in their own inimitable manner. Craven personally interrogates the prisoners, one of whom wills himself to die, rather than answer Craven. Meanwhile, in a secret installation, the villain of the piece, Vox, receives word that the Metal Men have taken his men prisoner.

Vox murders the bad news bearer, with the power of his voice, for daring to speak aloud in Vox's presence. Vox's monologues about his plan to expand his operation from merely selling weaponized prosthetics, to providing armies with cyborg soldiers. Soldiers Vox calls "Cyboriginals". Seeing an opportunity to improve his operation, Vox decides to abduct Magnus, to learn the secret of the Metal Men's shape changing abilities. A secret Magnus has just revealed to Craven. A squad of Cyboriginals attacks Craven's base. Lead molds himself into a shield to protect Magnus and Craven from a bazooka attack. The Metal Men engage the Cyboriginals in combat. The Cyboriginal's attack, though, is merely a distraction, hiding Vox's true objective, the abduction of Magnus. Vox makes a grab for Magnus. Iron molds himself into a protective shell around Magnus, and Craven.

Undeterred, Vox uses a giant electro-magnet, to simply cart Iron off, along with Magnus and Craven. The Metal Men move to rescue Magnus, but are ordered back, for fear that they will be taken, too. With Magnus, Craven, and Iron his prisoners, Vox begins interrogating Magnus, bent on discovering the secret of the Metal Men. When Magnus refuses to divulge the secret, Vox decides to cut off Magnus' head, and surgically pry the information from his brain. A squad of Cyboriginals mount a rescue operation to retrieve the Cyboriginals imprisoned on Craven's base. Craven offers to reveal the secret to the Metal Men's shape changing ability, in exchange for Magnus' life, as well as a cybernetic heart to replace his own failing pacemaker. Vox agrees. Upon returning to Vox's base, the Cyborginal rescue team reveals themselves to be the Metal Men.

Once Craven gives up the Metal Men's secrets, Vox activates the saw to remove Magnus head. The traumatic stress proves to much for Craven's weak heart. The Metal Men, amalgamated into one huge robot, burst into the room. Reversing the polarity on the electro-magnet, holding Iron, shoots Iron out like a cannonball. Upon impact, the amalgamated Metal Men are separated back into their individual selves. Not missing a beat, they continue their assault on Vox's installation. Mercury punches Vox's voice amplification device off his face, leaving him mute and powerless. Also no longer able to control the voice activated buzz saw closing on Magnus' neck. Quickly molding themselves into a giant catapult, the Metal Men hurl Lead into the saw blades, destroying them. Reunited, Magnus and the Metal Men take a moment to reflect on Craven's death.