Who is in "Countdown" Season 1? "Countdown" stars Jensen Ackles as Mark Meachum. He is joined by Jessica Camacho, Eric Dane, Bogdan Yasinski, Violett Beane, Elliot Knight, and Uli Latukefu.

Haas has made it clear that if Dane wants to do more, then the door is open for him. He wants Dane to be part of Countdown season 2, but the ball is completely in his court.