Roy Dotrice, Hannah Murray

Roy Dotrice and Hannah Murray have joined the cast of HBO's Game of Thrones, TVGuide.com has confirmed.

Dotrice, who lends his voice to the audiobook adaptation of George R.R. Martin's A Song of Ice and Fire, on which Game of Thrones is based, will play Pyromancer Hallyne, chief of the Guild of Alchemists. Murray, who appeared on the British version of Skins, will play Gilly, one of the many women living with Old Craster who wants to escape his oppression.

Liam Cunningham signs on for Game of Thrones

Dotrice and Murray are the latest to join an ever-growing guest cast for Season 2. Two weeks ago, Liam Cunningham signed on to play Davos Seaworth, along with Stephen Dillane as Stannis and Carice van Houten as Melisandre. Earlier, Gwendoline Christie was cast as Brienne, while The Tudors actress Natalie Dormer will play Margaery Tyrell.