HBO Teases New 'Game of Thrones' Documentary

Two angles facing left, which often indicate, "return to the beginning." Two angles facing right, which often indicate, "advance to the end." Warning: Spoilers ahead for the series finale of HBO's "Game of Thrones." HBO's documentary feature on the final season of "Game of Thrones," titled "The Last Watch," premieres Sunday, May 26 at 9 p.m. ET.