Katie Reul editor The action-packed final season of “His Dark Materials” will debut its first two episodes in a back-to-back broadcast on HBO Dec. 5, according to a teaser that premiered at New York Comic-Con. Season 3 will also be available for streaming on HBO Max. James McAvoy is making a significant resurgence in the series as Lord Asriel, who was absent from the screen for the majority of Season 2. The upcoming season largely focuses on Asriel rallying military forces to launch a holy crusade against the “Authority” — an antagonistic spiritual force that dictates his universe. “I’m gathering the greatest from every world to help me wage war,” Asriel reveals in the trailer.