Not quite. The star of Miss Fisher's Murder Mysteries is reported to be flinging off Phryne's 1920s bob hairdo, tassles and beads to take on a role in the coming season six of GoT in which she is part of a travelling theatre troupe - and her role-within-a-role has her pretending to be the icy, incestuous queen.

The Hollwood Reporter says Davis, who has also starred in The Slap, The Babadook and the two Matrix sequels, was spotted last week in Girona, Spain, filming a sequence. Fans posted photos and video from the set, showing her in the troupe, which travels through the fictional land of Braavos staging a play called The Bloody Hand.

According to Vanity Fair, the casting call describes Davis' character thus: "In her early 40s, she's an elegant actress with a travelling theatre company. Fun, charismatic, rum-drinking actress in the troupe."  It sounds perfect for Davis, given the roles she's taken in the past.

Lena Headey - who plays the real Queen Cersei - can breathe easy knowing her prized role isn't really under re-assessment. After all, the viperous Cersei doesn't take threats to her person very well at all, given the fate of more than a few characters around her...

A released chapter of the next and highly anticipated book in The Winds of Winter, the sixth in George R. R. Martin's A Song of Ice and Fire cycle, describes the troupe as putting on The Bloody Hand to tell the tale of events at King's Landing over the past few seasons. And there have been quite a lot of events, haven't there? 

The latest addition to season six, Davis joins other newcomers including Richard E. Grant, Freddie Stroma, Pilou Asbaek, Max von Sydow and Ian McShane.

Grant, says Vanity Fair, is also in the theatre troupe with Davis. His role had been a mystery, but it is now believed he will play the leader of the troupe, pretending to be King Robert. His character is described as specialising in "portraying drunken aristocrats." Again, that sounds perfect for the talented Grant, who first made his mark in Withnail and I (1987). 

Casting is probably one of the most frenzied departments of the vast production behemoth fuelling the incredibly successful HBO series. The character lists in Martin's books usually run to several pages, meaning there are always new roles to be filled in the TV adaptation.

That, combined with a constant storm of flashing sword-fights, beheadings, poisonings, gorings, zombifications, entombments, enchantments and various other gruesome deaths, also means roles tend to be short-lived. Actors must love it.