3.19, Memoria
Episode Details
Episode Description:
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 (recurring guest star 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.
Writers:
Alfred Gough
Writers:
Miles Millar
Directors:
Miles Millar
Air Date:
Wednesday, April 28, 2004 
No Chloe but a very important episode about Clark's past (his first look at Krypton) and the truth about what happened to Lex's brother Julian.