star Ellie Kendrick says the sixth season of the globally popular TV series enters "completely new territories".
The series, which is produced for HBO TV channel, is based on A Song of Ice and Fire books written by George R. R. Martin, and will premiere in New Zealand on April 25.
British actress Kendrick, who returns to play Meera Reed after a season away, said "we are entering completely new territories and have reached the end of the books' events."
She revealed that it "sounds weird to write the future of Game of Thrones without Martin".
Dutch actress Carice van Houten, who plays the role of priestess Melisandre, agrees with Kendrick.
"The new season will be a drastic change, from a historical point of view, for people who have read the books, but now the writers have had more artistic freedom," she told EFE.
The fifth season ended with the Myrcella poisoning by Ellaria Arena, in addition to the surprising murder of Jon Snow at the hands of a group of guards.
The death of Snow, played by Kit Harington, has sparked people's interest on social networks, blogs and newspapers and made the role of the mysterious Melisandre very special in the new season.
"In the sixth season, we will see a different side about Melisandre who lost faith and control after the failure of her plan," Van Houten added.
Maisie Williams also plays an important role in the new season, the role of Arya Stark, who became blind in the fifth season after the killing of Ser Meryn Trant.