Showtime’s upcoming “Halo” series has added three more series regulars.

Danny Sapani, Olive Gray, and Charlie Murphy have all joined the show, which is based on the video game franchise of the same name and is set to begin production this month in Budapest. They join previously announced series lead Pablo Schrieber, who will play the Master Chief, as well as Natascha McElhone, Bokeem Woodbine, Shabana Azmi, Bentley Kalu, Natasha Culzac, and Kate Kennedy. The series is currently scheduled to air in the first quarter of 2021.

Sapani will play Captain Jacob Keyes, described a dedicated military man, a war hero and a caring father. He finds that working alongside his daughter and his ex-wife is usually the cause of conflict rather than comfort. Sapani’s television credits include shows like “Harlots,” “The Crown,” “Doctor Who,” and “The Bastard Executioner.” His film credits include “Black Panther,” “Star Wars Episode VIII: The Last Jedi,” and “The Siege of Jadotville.”

He is repped by Gordon and French and Luber Roklin Entertainment.

Gray will play Dr. Miranda Keyes, a brilliant UNSC Commander who is dedicated to understanding the technology, language and culture of the Covenant, but she’ll have to learn to navigate the politics of the UNSC to get what she wants. In addition to the BBC’s “Half Moon Investigations,” Gray has appeared in “Sex Education,” “Fleabag,” “EastEnders,” “Dark Money,” “Pure,” and “The Story of Tracy Beaker.”

She is repped by Independent Talent Group in the U.K., UTA in the U.S., and Grandview.

Murphy will play Makee, an orphaned human who was raised by the alien Covenant and shares their contempt for humanity. In addition to her role as Jessie Eden on “Peaky Blinders,” Murphy’s screen credits include “Walk Invisible: The Brontë Sisters,” “Happy Valley,” “The Last Kingdom,” “Misfits,” and “Ripper Street.”

She is repped by Troika.

It was announced last June that Showtime had ordered a 10-episode series based on the megahit video game after it had been in development at the premium cabler for years, though its order has since been trimmed to nine episodes. Kyle Killen and Steve Kane will serve as co-showrunners and executive producers. Darryl Frank and Justin Falvey of Amblin Television will also executive produce along with series director Otto Bathurst and Toby Leslie for One Big Picture, Scott Pennington for Chapter Eleven, and Karen Richards.

The series is produced by Showtime in partnership with 343 Industries and Amblin Television. It will be distributed globally by CBS Studios International.

(Pictured: Danny Sapani, left; Olive Gray, center; Charlie Murphy, right)