Ian Somerhalder Joins The Cast

Ian Somerhalder Joins The Cast

Ian Somerhalder, who played Boone on ABC's hit "Lost," has joined the cast of the Vampire Diaries.Ian Somerhalder

Somerhalder is set to play Damon, a smug vampire who can go from playful to evil in a split second.

Also joining the cast are Paul Wesley ("24," "Everwood," "Army Wives"), who will play Damon's brother Stefan, Zach Roerig ("Friday Night Lights"), who will play the jock Matt, and Kayla Ewell ("Entourage"), who will play Matt's sister.