A madman with telekinetic powers causes chaos in Metropolis. Meanwhile, when Clark finds out he is unable to have children with Lois, they decide to get a second opinion from Lois' father.
Lois and Clark find out from Dr. Klein that they cannot have a child together because Superman's Kryptonian biology with a human is incompatible. They decide to ask Lois' father, Sam, for help but they know they will have to tell him that Clark is Superman. Sam is shocked by the news but he promises to see if he can help them while at the same time everyone is trying to keep the secret from Lois' mother Ellen.
They also discover that they cannot adopt because Lois is a top reporter who always gets in danger.
Meanwhile, Dr. Klaus Mensa, nicknamed "fat head" because of his enormous head (which he hates being called) is released from prison after five years where he has developed great power with his mind. He wants revenge on those who betrayed him and wants to start over alone.
First he kills one of his former employees Carter Clavens and then goes after Dr. Mischa who is Sam's research assistant, but Misha tells him that he is working on a new weapon that will help Mensa control anyone with his mind at will, which of course is untrue.
Misha then suspects that Sam is working on a secret project so he uses truth serum on him which makes him reveal Superman's identity to which he tells Mensa.
Mensa decides to kidnap Clark and Lois' parents as a reassurance that Superman will not interfere with his plans of stealing millions of gold from the bank.
However with Misha's help, The Kents and Lanes fool Mensa by telephone that they are being killed, but Superman knows that they are fine after hearing a quote Lois' father says. He tries to capture Mensa, but he escapes and rushes back to the laboratory.
He demands that Misha hook him up to the new Bummer-Be-Gone machine, believing it to increase his abilities, but it only takes his telekinetic powers away, while also erasing memories of everything he had learned and anything unpleasant. Sam also has the memory of Clark's alter-ego taken away. Mensa is then arrested.
Later Lois and Clark are reflecting on not being able to have children when they hear a noise downstairs and go inside the kitchen to discover a baby wrapped in a blanket with Superman's "S" shield on it. With it is a note from someone who knows them saying "Lois and Clark, this child belongs to you."
Their parents come downstairs and Lois and Clark show their baby to them, which fills everybody with happiness as they finally have the child they had always wanted.