Microsoft, 343 Industries, and Showtime announced that the “Halo” TV series has officially entered production, as one of the most influential gaming franchises heads to a new medium.

The 10-episode season is scheduled for release at some point in the first quarter of 2021. While the producers have yet to announce any significant details regarding the overall plot of “Halo,” except that it takes place during the Human-Covenant War, the casting — some of the characters have been dead for a while in the games — suggests it will be set well before the events of the original 2001 Halo: Combat Evolved.

The Halo franchise began in 2001 as a launch title for the original Xbox. Its impact on the video game industry is difficult to overstate; Halo provided the fledgling Xbox with its first “killer app,” and its various features went on to heavily influence the first-person shooter as a genre. (To this day, most action games still feature Halo-style regenerating health.) Halo is still a tentpole franchise for Xbox consoles, and the various games in the series have sold over 77 million copies worldwide.

Now it is getting a TV series, reflecting Halo’s extensive staying power as a multi-billion dollar franchise.

According to Deadline, the show is being made in Budapest, with Pablo Schreiber (“American Gods”) as series protagonist Master Chief and “Designated Survivor’s” Natascha McElhone playing the dual role of both the AI Cortana and her creator, the renegade scientist Dr. Catherine Halsey. “Halo” is a joint production between Showtime, 343 Industries, and Steven Spielberg’s Amblin Entertainment, with Otto Bathurst (“Black Mirror”) attached as director.

This week’s announcement also included the addition of three new actors to the cast. Danny Sapani (“Penny Dreadful”) plays Captain Jacob Keyes, with English actress Olive Gray as his daughter Dr. Miranda Keyes. Charlie Murphy (“Peaky Blinders”) plays Makee, a human who was orphaned and subsequently raised by the alien Covenant.

Other actors attached to the project include Bokeem Woodbine, Shabana Azmi, Bentley Kalu, Natasha Culzac, and Kate Kennedy.

The cast is assembled. The table reads are complete. Production on the @Showtime Halo series is about to begin! pic.twitter.com/KNrPLYx260 — Halo on Showtime (@SHO_Halo) November 8, 2019

According to the current casting, the series appears to be sticking surprisingly close to the game plot. Kalu, Culzac, and Kennedy are all playing the roles of Spartan supersoldiers like the Master Chief, with Kalu’s character Vannak-134 (all Spartans in the Halo EU are described by a first name plus a number; the Chief himself is John-117), described as the Chief’s deputy, and Azmi as a brand-new character who heads up the intelligence branch of the United Nations Space Command.

There’s a lot for a TV show to work within the Halo universe, and the show already seems to be going out of its way to make sure it’s a reasonably faithful adaptation.

It’s going to be a strange ride. Halo has had an extensive “expanded universe” almost from the beginning, with many details of its overarching story disclosed in novels including First Strike and Contact Harvest, but the games tended to keep those events at arm’s length.

Starting with Halo 4, however, the games began to draw on more details from the expanded universe. Catherine Halsey in particular is a controversial figure both inside and outside the story, so putting her on center stage in the show is a bold decision. There’s a lot for a TV show to work within the Halo universe, and the show already seems to be going out of its way to make sure it’s a reasonably faithful adaptation.

I’d be lying if I said I wasn’t a little wary of Makee as a concept, though. One of the consistent things about the Human-Covenant War, which provided the central conflict of the first three Halo games, was that it was a genocidal purge, begun and led by religious zealots. It’s difficult to imagine a set of circumstances under which any member of the Covenant would’ve let a human live, let alone raised her as one of their own.

The “Halo” TV show was first announced last June, which marked a potential end to a 14-year period of development hell for a live-action adaptation of Halo. The production subsequently lost its initial director, Rise of the Planet of the Apes’ Rupert Wyatt, due to scheduling conflicts. Wyatt was quietly replaced by Bathurst the following February.

Halo’s original creator, Bellevue, Wash.-based Bungie, went independent from Microsoft in 2007. Microsoft promptly founded a new third-party studio, 343 Industries, based in Kirkland, Wash., to continue to develop the series. 343’s next game, Halo: Infinite, is slated to come out at the end of next year as a launch title for Microsoft’s next console, which is still known by the codename of Project Scarlett.