At the TCA summer press tour, Showtime made six casting announcements for its upcoming live-action Halo TV series based on the iconic video game franchise. These newcomers will join actor Pablo Schreiber, who was cast as Master Chief back in April . The series will premiere in the first quarter of 2021."[Natascha] McElhone will star as two characters -- Dr. Catherine Halsey, the brilliant, conflicted and inscrutable creator of the Spartan supersoldiers and Cortana, the most advanced AI in human history, and potentially the key to the survival of the human race," according to a press release from Showtime.