[With Annihilation now available on Hulu, we’ve decided to repost this article.]

Spoilers ahead for Annihilation.

Movies are not mystery boxes. There is no “answer” because art isn’t a game or a puzzle to be solved. It’s subjective, so it’s open to interpretation. Great art invites interpretation, not by being needlessly obtuse, but by encouraging the viewers to explore certain ideas and concepts that are presented in a unique way.

Alex Garland’s new sci-fi film, Annihilation, is great art. It’s also a movie that’s bound to frustrate and infuriate some viewers who believed they were getting a sci-fi action movie and instead got Tessa Thompson sprouting leaves and people getting attacked by a bear with human screams. It’s horrifying, but in a specific way. However, like last year’s mother!, Annihilation exists largely in the realm of metaphor. It’s meant to put you in the same dreamlike state of the characters, offering explanations for what’s happening, but also never announcing its themes as it tries to weave subtext into the text.

So what’s exactly happening with Annihilation? It’s a movie about cancer.

No one in the movie says, “It’s about cancer,” but it’s clear within the first fifteen minutes that the premise of Garland’s movie is basically, “What if the Earth—that is, the planet itself—got cancer?” And then the movie moves forward from that premise. The “plot” may be about a biologist, Lena (Natalie Portman), who, along with fellow scientists Dr. Ventress (Jennifer Jason Leigh), Thorensen (Gina Rodriguez), Sheppard (Tuva Novotny), and Radek (Tessa Thompson), heads into The Shimmer, an unexplained phenomenon, and searching for answers. But the movie is about is cancer, and you can see that consistently throughout.

We immediately get it right from Lena’s first lecture at Johns Hopkins where she talks about cell division, and how cells rapidly divide and mutate. We then cut back three years ago when something struck a lighthouse in the Southern Reach and then it started expanding. The unexplained phenomenon makes a good stand-in for how cancer strikes. Everything is normal, and then it’s not, and in its place is something that’s mutating and, like The Shimmer, expanding. Yes, we can talk about risk factors, but there are perfectly healthy people who still get cancer. It’s not that cancer is inexplicable, but rather our understanding of it is still evolving.

Once Lena and the team are inside the Shimmer, they start noticing mutations, and those mutations stand in for the cancer (the tumor at the heart of the Shimmer) affecting other cells. Garland is basically taking a biological phenomenon and staging something similar to Fantastic Voyage, except instead of the scientists shrinking down to go inside someone’s body, the body they’re investigating is the Earth. Everything gets messed up because of mutations, and as Radek later explains to the group, they’re basically inside of a prism, so everything is refracting. Minds, bodies—everything gets screwed up because that’s what cancer does to a healthy body.

But Garland presents this in a very specific way. It’s not like The Cloverfield Paradox, where anything can happen and nothing is explained so one dude is filled with worms and another dude has a severed arm that offers hints when you’re stuck. Annihilation remains consistent, constantly showing mutations, but mutations as they would occur on a body. Garland wisely abstains from presenting everything as simply gross or beautiful. There’s a calculated indifference. Life grows and mutates, and sometimes you might see something beautiful like the white, skeletal deer with branches for antlers, and sometimes you get ScreamBear, the Bear Made of Screams.