Dark Matter author breaks down the biggest changes from the book

Warning: This article contains spoilers from the Dark Matter finale, "Entanglement."

All in all, Apple TV+'s Dark Matter was a pretty truthful adaptation of Blake Crouch's 2016 sci-fi novel, which makes sense given that Crouch was also the series' showrunner. But like with any book-to-screen adaptation, some changes had to be made. So although the show ended with Jason (Joel Edgerton) and his family reunited and headed to a world where they could be safe — one chosen by his son — there were some major story changes along the way.

Entertainment Weekly spoke with Crouch and executive producer Matt Tolmach about some of those big decisions.

Jason2's extended arc

Not only did the show follow Jason2 for more of the story, but it ended with him helping Jason1 get away with Daniela (Jennifer Connelly) and Charlie (Oakes Fegley), whereas in the book, Jason1 killed the version of himself that set this whole thing into motion.

"A lot of that came from Joel Edgerton," Crouch says. "Joel was just like, 'I don't want to demonize Jason2. At the end, it would be really interesting to see some real growth on his part.' There's not a lot of growth on Jason2's part, if I'm being honest, in the book. And because we're spending so much time with Jason2 in the show, and we see all the trouble he's gone through to try to make this life work, it felt right that there'd be some self-analysis of who he is. But that all really started with Joel."

Tolmach adds: "We talked about who's the bad guy and the truth is, the whole idea is so powerful because it suggests that there are different iterations of who we are. And so suddenly, having a mustache-twirling Jason would've been completely disingenuous because the power of it is that it's those small choices we make that send us down a different path. But you don't suddenly become an arch super-villain because you made a different choice. Those not-great character qualities also exist within Jason1."

Ryan's fate

One of Jason2's darkest choices? Leaving Ryan1 (Jimmi Simpson) trapped in another world, something that did not happen in the book.

"I think there's a lot under the surface of the show that is never really spelled out," Crouch says of the Jason-Ryan relationship. "I always imagined that Ryan and Daniela had a little bit of a chemistry, a little bit of a spark between them, and I think there's also always been some professional jealousy between Jason and Ryan. Even Jason1, you see a little bit of that loss. So for Jason2, we pushed that idea to the limit. And then you get into plotting things and it makes sense that Ryan comes across this ampule Daniela brings in, and what's he going to do? He's going to use this thing at the core of our show to help solve his problem."

Max

In the book, Charlie doesn't have a twin that died, a story idea that Crouch says came from Edgerton. "Joel had kids later in life and had just had twins, and one of the things he said, which was such a breakthrough for us, was that it would be one thing for Jason to want to return home to a perfect world where the family, for the most part, had sailed through without any real trauma or grief. But him wanting to go back and embrace his life despite the pain made Jason's journey, in some ways, even more heroic. The moment he said that, we were all like, 'Well, obviously we're going to do that.'"

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Daniela figures it out

Although Daniela doesn't fully connect all the pieces of the puzzle, she gets much closer to figuring things out in the show than she ever did in the book.

"The book is just Jason's point of view, and one of the things we were excited about in the show was to build out this other plot line," Crouch says. "When you hire someone like Jennifer Connelly, they're going to want to solve a lot of things for themselves. So we really wanted to just play with the idea that, would you know if your spouse just wasn't your spouse anymore, but they looked like them in every other way? It's something that I never really explored in the book except for one very brief chapter. So that was one of the most fun things about doing the show, is building out Daniela's experience suspecting that her husband is an imposter."

Jason1 doesn't sleep with Daniela2

In the book, when Jason1 discovers Daniela2, the two of them end up sleeping together before she's killed. In the show, they only kiss.

"We had a lot of discussions. So many people would've had an absolutely polarizing reaction to that," Crouch says. "Some people would be like, 'I get it's his wife.' But I think my fear was there would be some contingent of the audience that would be like, 'Nope, that is not a good guy.' And then we lose their allegiance and their sympathies for Jason at the end of the second episode."

"The characters themselves are torn," Tolmach adds. "That's the most honest version of it. You're the same person, but you're not. And it allows the drama to encapsulate exactly what you're getting at without committing to it."

All nine episodes of Dark Matter are streaming now on Apple TV+.