Although there's been no official announcement yet, it looks like we know the identity of at least one new addition to the cast of "Game of Thrones." According to the New Zealand Herald, Keisha Castle-Hughes spilled the beans to friends that she's officially on board for Season 5, in a role of a deadly Dornish Sand Snake.

For those not in the know, the recently-deceased Oberyn Martell was both a deadly swordsman and a prolific sower of wild manly oats back in his home country of Dorne. And though his bastard daughters, known as the Sand Snakes, earned only a passing mention in Season 4, a casting call from earlier this year confirmed that they would be getting some screen time when the show returns in 2015. Which of the ladies Sand will Castle-Hughes be playing? Some speculation (with book spoilers, beware) below.

The Sand Snakes in George R. R. Martin's "A Song of Ice and Fire" series include a bevy of Oberyn's daughters by any number of different Dornish dames, but the show is set to concern itself only with the main three: Obara, Nymeria, and Tyene. After Oberyn's death at the hands of The Mountain, his daughters -- particularly Obara, a fierce and accomplished fighter -- are out for revenge in a major way, goading their uncle Prince Doran Martell to declare war on King's Landing.

The Herald speculated that the Maori actress has just the right look to play the dark-skinned and beautiful Nymeria, but Vanity Fair is predicting (or at least hoping) that she'll see some action in the role of Obara. Among their reasons for wanting Castle-Hughes in the role of the eldest, most violent daughter: the chance of seeing her have a much-discussed, not-from-the-books fight scene with a "major character" who may or may not be Jaime Lannister.

Castle-Hughes is best known in the U.S. as the star of "Whale Rider," which earned her an Oscar nomination back in 2004. A role on "Game of Thrones" would be her biggest break since then, and a career-invigorating move for the actress who recently moved to Los Angeles in order to pursue more high-profile work.