Game of Thrones Season 4 Spoilers!

HBO and the producers of Game of Thrones aren't wasting any time getting underway with the show's fourth season. In fact they've already added Doctor Who and Sherlock actor Mark Gatiss to the cast.

But what character will Gatiss play? Rumors surrounding Season 4 of Thrones indicate a few new characters in play. Mace Tyrelly, father of Margaery will be a major player series, and probably the best fit for Gatiss.

Gattis' cast announcement comes in the wake of Pedro Pascal announcing he will be cast as Prince Oberyn Martell, the Red Viper.

"This was a tough one," says Thrones showrunners Benioff and Weiss about casting. "The Red Viper is sexy and charming, yet believably dangerous; intensely likable, yet driven by hate. The boys love him, the girls love him, and he loves them all back. Unless your last name is Lannister. We found a fellow who can handle the job description and make it seem effortless. He wasn't easy to find and he won't be easy to stop."

Expect more updates as Comic-Con 2013 approaches.

Game of Thrones Season 4 premieres on HBO in Spring 2014.