The Metal Men are responding to the massive amount of mail they have received, from their fans, in response to the naming of Nameless. As usual, a verbal squabble breaks out between Platinum and Mercury. Lead comes across a personal letter for Doctor Will Magnus. Fearing that Magnus has received a love note from one of his model girlfriends, Platinum peers over his shoulder to read the private message. The letter turns out to be a death threat, to Magnus, from someone, or something, called "B.O.L.T.S." When the letter begins to smoke, Platinum snatches it from Magnus' hands, then shoves her creator behind Lead. Platinum smothers the letter's explosion with her own body. Magnus carries Platinum's inert form to the Robot Recovery Room, for repairs.

Enraged at the attack on their creator, the Metal Men angrily vow to bring B.O.L.T.S. down. From that point onward, the Metal Men begin screening Magnus' mail. Magnus receives an invitation to attend the Mechanical Men Inventors Association's latest exhibition. Fearing a trap, the Metal Men plead with Magnus not to attend. Magnus, though, sees it as an opportunity to smoke B.O.L.T.S. out into the open. During one inventor's demonstration, his robots suddenly cease following his orders, and begin attacking the audience. Swarming Magnus, the robots seize him, then carry him away, despite the best efforts of law enforcement officers to stop them. Magnus is brought before B.O.L.T.S., a gigantic robot, sent by Communists to destroy democracy.

As Magnus anticipated, the Metal Men have followed him, and arrive in time to confront B.O.L.T.S. Anti-Aircraft guns project from B.O.L.T.S.' head. Under heavy fire, the Metal Men's jetaway is shot down from the sky. Gold molds himself into a slide, to carry the Metal Men safely down to the ground. Alloying himself with Tin, Iron molds himself into a large fist, to knock the flak from the sky, until the Metal Men can reach the ground. B.O.L.T.S. switches armaments and sweeps the Metal Men with his flame-thrower. With Gold, Tin, and Lead serving as the weights, Platinum fashions herself into a bolo, that Iron then tangles B.O.L.T.S. legs in, toppling the giant robot. Iron then attacks the robots holding Magnus, and destroys them all.

B.O.L.T.S. lays down a smoke screen to cover his escape. After yet another arguement breaks out between Platinum and Mercury, Magnus angrily shuns his Metal Men, in favor of spending time with a human companion. Magnus' date, though, furiously storms out of his car, when she realizes that his mind is clearly on someone other than her. En route back to his laboratory, Magnus is ambushed by B.O.L.T.S. Magnus fires rockets from his convertible, but they explode harmlessly against B.O.L.T.S. heavily armored chest. Magnus is taken prisoner by B.O.L.T.S. Magnus radios the Metal Men to come to his rescue. Left behind for her safety, Nameless, nonetheless, opts to follow the Metal Men into combat.

The Metal Men arrive just as B.O.L.T.S. is placing Magnus, still in his convertible, onto the conveyor belt of a junk stamping press. Platinum leaps into the car with Magnus, but B.O.L.T.S. crushes the car around them, trapping them inside. The Metal Men launch themselves against B.O.L.T.S, and all crumple against his armor-plating. The broken Metal Men are also placed on the conveyer. Nameless races to share the team's fate. As soon as B.O.L.T.S. lays eyes on Nameless he falls madly in love with her. B.O.L.T.S. chases Nameless into a refrigerated train car. Attempting to flee from the amorous automaton, Nameless leaps onto an electric fence. When B.O.L.T.S. kisses Nameless, the high voltage of the fence is super conducted through Nameless' frigid tin form, electrocuting B.O.L.T.S. Nameless shuts down the conveyor belt, saving Magnus and Platinum. Magnus brings the Metal Men back to his laboratory to begin repairs.