Amazon’s Warhammer 40K TV show writer Mike Flanagan says penning the show is like “climbing my adaptation Everest”

Mike Flanagan in front of Warhammer 40K key art

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Last Updated: 16 October 2026

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Horror film and TV icon Mike Flanagan is currently penning the scripts for Amazon Prime’s Warhammer 40K series. Alongside potential future series of his just-released show Carrie and a TV adaptation of Stephen King’s The Dark Tower, Flanagan is working alongside actor Henry Cavill to bring Games Workshop’s Grimdark universe to life.

As many would expect, this has not been an easy task. While Flanagan has decades of experience transforming King’s interconnected horror universe into TV and film, Warhammer 40K is an even denser project to tackle.

“I feel like I’m climbing my adaptation Everrest right now,” Flanagan told The Process Unlocked (thanks, IGN) “because I’ve been working, and this is out there so I can talk barely a little bit about it, but I’ve been working on Warhammer [for Amazon].”

When it comes to Flanagan’s upcoming adaptation of The Dark Tower, which many have claimed is too dense to adapt, he explained that the process is to adapt the pre-existing structure of the novels. “You do the books,” he said.

“Stephen King is a genius in how he structures the Dark Tower,” he continued, “because he starts this giant world-building, potentially overwhelming story, with two people in a landscape without detail. It’s the simplest start.”

Flanagan explained the introduction of the first book, The Gunslinger, opens with “one of the most perfect lines of any book” as it tells everyone exactly where to start. “’The man in black fled across the desert and the gunslinger followed’. It’s two characters, there’s a clear objective; one is running away, one is pursuing, and it’s a desert… he adds a universe one brick at a time”.

“The challenge is how do you get in? And so that to me that’s really a brutally difficult adaptation.”

Mike Flanagan on adapting Warhammer 40,000 to TV for Amazon Prime

The horror icon explained that, for that adaptation, “70% of my job is done for me by Steve [King]”, but Warhammer 40K is a much more difficult task. “Warhammer is not like that,” he said, explaining that the sheer density of the universe and the scale of the series’ extended media, 700 books, versus The Dark Tower, eight books… kinda.

“These are novel length,” Flanagan said. “These are not small. But there are so many characters. It takes place over so many thousands of years. There’s so much there. The challenge is how do you get in?”

This isn’t the same TV show, but Amazon also hosts Secret Level, and it’s awesome Warhammer episode, which relates to Space Marine 2.

Newcomers to the series are always asking for the perfect entry point to Warhammer 40K, and that’s a really hard question to answer. Most fans have their own entry point, whether that’s a novel, a game (Dawn of War for myself), or even just a YouTube lore explanation at this point. The series has evolved so much that some people enter the franchise just painting a model, not even playing the game they’re made for.

Flanagan explained that Warhammer 40K is “really a brutally difficult adaptation, but it’s been so fun for it”. As far as we know, the writer is still in the midst of penning the first scripts for the TV show, and it seems that the direction of the series’ overall story has already been somewhat decided.

With Flanagan at the helm, there is a hope that there will be a horror focus for the upcoming Warhammer 40K TV series. Unfortunately, we know absolutely nothing about the series other than the fact that its in development, and Henry Cavill is involved.