HBO has signed on Irish actress Danielle Galligan to play a character called Sarra in season eight, according to fan site Watchers on the Wall. The only character called Sarra in George RR Martin's novels is a descendant of deceased villain Walder Frey.

Game of Thrones fans will recall Frey is the nonagenarian responsible for the notorious 'Red Wedding'. He is slain by Arya Stark at the end of season six, before the rest of his male line are wiped out at the beginning of season seven.

As Frey's numerous sons choke and splutter on their wine, Arya turns to his widow and says if anyone asks what happened to tell them "the north remembers".

"Tell them winter came for House Frey," she said.

However winter hasn't come for all of House Frey - at least, not yet. It's a bit of a curveball from showrunners given season eight is due to comprise of just six episodes.

Since the Watchers on the Wall story broke, many fans have been questioning why the show might introduce new characters instead of tying up existing plot lines. However, it should be noted Sarra Frey has appeared in Game of Thrones before.

Walder Frey's granddaughter - played by an uncredited cast member - showed up in season three. She is one of the girls offered to Robb Stark as a potential wife.

Since fans went crazy over the sassy - and extraordinarily young - Lyanna Mormont in seasons six and seven, ushering Sarra Frey into the spotlight could be another attempt at creating a memorable minor character.

Or could another wedding be on the cards? As long as it isn't another red wedding, fans shouldn't have too much to worry about (other than the hordes of undead marching down from the north).

Game of Thrones season eight is expected to hit television screens either next year or sometime in 2019.