Lois' sister Lucy (Roxana Zal) moves back into the town with her new boyfriend Johnny (Scott Valentine), who Lois does not like and tries to convince Lucy that he is no good for her and using her, leading them to fight. In the meantime, two scientists Rollie and Emmet Vale (Christian Clemenson and John Rubinstein) create robots that they use to rob jewelries. After Johnny gets shot by police during a robbery, the two scientists take his head and transform him into a cyborg that is powered by Kryptonite. Under the name Metallo, Johnny uses his new body to steal money from ATMs and also tries to defeat Superman. On their first confrontation, Superman is defeated due to the kryptonite that is hidden into Johnny's body. Superman realizes the existence of the kryptonite and the next time they meet, he knows how to fight Johnny without him getting affected by the kryptonite. Johnny gets defeated while one of the scientists get arrested and the other one runs away with the kryptonite.