Production has begun on the second season of Netflix’s 3 Body Problem, and the series is tapping into its Game of Thrones roots for its Season 2 cast. Created by David Benioff, D.B. Weiss, and Alexander Woo, the hit Netflix series is ramping up with casting announcements, although few plot details have been revealed.

Netflix is staging a Game of Thrones reunion. Alfie Allen has joined the cast of 3 Body Problem, reuniting TV’s erstwhile Theon Greyjoy with Thrones creators David Benioff and D.B. Weiss. Character details are being kept under wraps.

The sci-fi epic has added a trio of new cast members to its upcoming season, which has officially begun production.