Believing that key information about his father's past was lost when his memory was erased, Lex decides to join an experimental program with Dr. Garner to regain the information so he can turn his father over to the FBI. Knowing that Lex will discover his secret if he regains his memory, Clark tries to stop him but is caught by Lionel and the doctor and exposed to the same radical treatment so that Lionel can solve the mystery of Clark's past.

Lex is given an envelope with damaging information that will destroy Jonathan's life and must decide whether he will use it as it will also bring harm to Clark and Martha. Before he can decide what to do, Lex is shot and falls into a coma. He dreams that his mother visits him and shows him the life he could lead if he walks away from his father and LuthorCorp. In this alternate life, Lex is happily married to Lana with a baby on the way. Meanwhile, Chloe asks Clark to use his powers to deliver Christmas presents to needy kids.

Distraught over her break-up with Clark, Lana goes to a rogue medical student who experiments with a dangerous kryptonite-based serum that allows people to flat-line but see their dead loved ones. Lana attempts to see her dead parents using the serum and when Clark returns from Honduras to help her, the doctor injects him with the serum and Clark speaks with his dead father...who warns him that Lionel knows his secret. Meanwhile, Lionel continues working to get closer to Martha, and Lex has a near-death vision of his mother.

Lex tracks the amnesiac Kara to Detroit, where Lois follows him. An obsessive busboy infatuated with Kara shoots Lex, and Chloe has to determine whether to heal him or not.