Alex Garland's Annihilation is coming together, and the details are extremely encouraging. Natalie Portman and Jane the Virgin's Gina Rodriguez both signed on in the past few months, and this week, The Wrap reported that Creed's Tessa Thompson is the lead contender for the third major role. After a long limbo, Garland's self-declared followup to Ex Machina is actually happening. The film is expected to start shooting next spring with studio backing from Paramount, on track for a 2017 opening.

It's an exciting, risky move, largely because of the source material. Annihilation the book was one of the best science fiction stories to come out of the last few years — and before Garland got involved, I probably would have told you it was unfilmable. The story focuses on a four-person mission exploring a mysterious zone (called Area X) over the course of a few days. It's a perfect, simple sci-fi premise, and Vandermeer uses it to explore really strange ideas about consciousness, science, and psychological control, without ever straying too far from the basic question of what the hell is going on in Area X. By the end, he's staked out new territory for the whole genre, getting way, way weirder than anything Hollywood has taken on in recent years.

Garland has said he won't track the novel beat for beat, but the story plays to some of the same themes he pulled off so well in Ex Machina, like liminal humanity and the uncanniness of nature. It's even got honest-to-god action scenes (monsters! shootouts!) although they don't play out the way you'd expect. With the latest news from The Wrap, we also know more or less everyone who we'll see on screen, since the three main characters make up the bulk of the screen time. Portman has already shown a gift for paranoid intensity, which is exactly what the story calls for.

If it works, it could open up a new space for smart, mid-level genre films — a kind of middle ground between Star Wars and Upstream Color. And since the industry loves a franchise, it's worth noting that Annhiliation's just the first part in a trilogy, getting progressively more bewildering as it goes along. If the first movie does well, Garland will have license to follow the books into even murkier waters.