EARTH: Lex and Clark adopted by Kents

As children in Smallville, Lex Luthor begins to suspect that Clark Kent and Superboy are one and same after an accident in Lex's lab leaves him bald. To safeguard his secret and keep the Kents safe, Superboy decides to leave Smallville. Lex then takes the opportunity to ingratiate himself with the Kents to confirm his theory about Clark Kent and Superboy. However, he is won over by the kindness of the Kents when they decide to adopt him and becomes Superboy's adopted brother when he decides to return.

As they grow to adulthood, Lex helps to keep Superman's secret identity while he works on scientific advancements to help mankind. However, Pete Ross, who has married Lana Lang, is revealed to be a crooked businessman and Superman's worst enemy. One of his plots very nearly kills Superman, but Lex uses one of his inventions to give himself superpowers to save his brother. Unfortunately, a defect in the invention kills the user after a short time and so Superman is left to mourn his brother, Lex Kent.