In the first major casting news for season 4 of “Game of Thrones,” HBO has cast “The Good Wife” actor Pedro Pascal to play Prince Oberyn Martell.

According to the books, the character is nicknamed “the Red Viper” and comes to Kings Landing seeking revenge for the death of his sister who was murdered by the Hound’s brother Gregor “The Mountain” Clegane.

The interesting thing about this casting for fans of the show (SPOILER alert) is the hint that we may be seeing “The Mountain” again, who was last seen chopping the head off of a horse after he loses a jousting match to Ser Loras Tyrell. The character has not appeared again on this show but did play a pivotal part in the eventual downfall of Ned Stark.

Game of Thrones” begins production next month and the fourth season will premiere next spring.

Pascal is repped by Innovative Artists and Authentic Talent and Literary Management.

EW.com first broke the news of Pascal’s casting.