To regain key incriminating information about his father's past that he lost when his memory was erased, Lex joins an experimental program headed by Dr. Garner (Martin Cummins). Knowing that Lex will also remember the secret of Clark's powers if he regains his memory, Clark tries to stop him -- but Lionel and Garner capture Clark and expose him to the same radical treatment, hoping to reveal his mystery.

Season 3 | Episode 19

Allison Mack

as Chloe Sullivan

Annette O'Toole

as Martha Kent

Erica Durance

as Lois Lane

John Schneider

as Jonathan Kent

Kristin Kreuk

as Lana Lang

Michael Rosenbaum

as Lex Luthor

Tom Welling

as Clark Kent