After his schoolmate, Cyrus Krupp (Jeremy Lelliott), claims to be an alien and seemingly proves it by using heat vision, Clark investigates and begins to believe that the boy is from Clark's home planet, Krypton. Meanwhile, when Helen discovers a locked room in the Luthor mansion, she demands to know what is inside -- and Lex must decide whether to admit the truth about his ongoing investigation of Clark.

Season 2 | Episode 18

Allison Mack

Chloe Sullivan

Annette O'Toole

Martha Kent

Erica Durance

Lois Lane

John Schneider

Jonathan Kent

Kristin Kreuk

Lana Lang

Michael Rosenbaum

Lex Luthor

Tom Welling

Clark Kent