On the day of Lex and Lana's wedding, Lex receives a call from a doctor who threatens to tell Lana the truth about her baby. Meanwhile, Lana begins to have second thoughts about marrying Lex. Clark comes to his own realization -- he can't let Lana marry Lex -- and decides to tell her his secret. But no one is prepared for what happens when Lionel steps in.

Season 6 | Episode 16

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