Photo Flash: First Look - 'Oathbreaker' Episode of HBO's GAME OF THRONES

Below, get a first look at the next episode of HBO's GAME OF THRONES titled "Oathbreaker" airing this upcoming Sunday at 9 pm ET/PT.

Based on the bestselling fantasy book series by George R.R. Martin, HBO's Emmy®- and Golden Globe-winning series GAME OF THRONES is an epic story of treachery and nobility set on the continent of Westeros, where summers and winters can last years, and only the lust for power is eternal.

Returning series regulars on GAME OF THRONES this season include: Emmy® and Golden Globe winner Peter Dinklage (Tyrion Lannister), Nikolaj Coster-Waldau (Jaime Lannister), Lena Headey (Cersei Lannister), Emilia Clarke (Daenerys Targaryen), Aidan Gillen (Petyr "Littlefinger" Baelish), Diana Rigg (Lady Olenna Tyrell), Sophie Turner (Sansa Stark), Maisie Williams (Arya Stark) and Jonathan Pryce (the High Sparrow).

Additional returning series regulars this season include: Alfie Allen (Theon Greyjoy), John Bradley (Samwell Tarly), Dean-Charles Chapman (Tommen), Gwendoline Christie (Brienne of Tarth), Liam Cunningham (Davos Seaworth), Natalie Dormer (Margaery Tyrell), Nathalie Emmanuel (Missandei), Jerome Flynn (Bronn), Iain Glen (Jorah Mormont), Isaac Hempstead-Wright (Bran Stark), Conleth Hill (Varys), Kristofer Hivju (Tormund Giantsbane),Michiel Huisman (Daario Naharis), Michael McElhatton (Roose Bolton), Hannah Murray (Gilly), Iwan Rheon (Ramsay Bolton), Carice van Houten (Melisandre), Indira Varma (Ellaria Sand) and Tom Wlaschiha (Jaqen H'ghar).

New cast members for the sixth season include: Pilou Asbaek, Essie Davis, Souad Faress, James Faulkner, Richard E. Grant, Ian McShane, Joe Naufau, Freddie Stroma and Max von Sydow.

Photo credit: Helen Sloan/HBO unless noted