When Chloe accidentally inhales a mysterious gas, she discovers that it gives her the ability to get the truth from anyone who comes in contact with her -- and she goes to the Kents to find out Clark's secret. However, her new power is not without its consequences, and Clark must find an antidote before she discovers too much about him or, worse, dies.

Season 3 | 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