Sci-fi is the best film genre there is. You may feel differently, but for me, nothing comes close to what sci-fi can do in terms of scope, imagination or provocation. My favorite films from the past few years have all been sci-fi; “Blade Runner 2049” last year, “Arrival” the year before that, and even “The Force Awakens” the year before that. This year, I was very much looking forward to writer/director Alex Garland’s “Annihilation.” Garland helmed 2015’s critically acclaimed “Ex Machina,” a film that works on a small scale but presents broad implications about humanity and our relationship with technology, so I was curious to see what he would do with “Annihilation.” Even as I write this review, I’m still not entirely sure what I just saw.

“Annihilation” stars Natalie Portman as Lena, a biologist who embarks on a mission with a group of scientists into a mysterious, rapidly expanding area called “The Shimmer,” a place where inexplicable biological phenomena and rapid mutations have occurred. That’s an extremely vague synopsis, because I probably couldn’t describe the events that follow even if I wanted to.

Let’s start with the concrete things I can say about “Annihilation.” Visually, the film is stunning. Being inside the Shimmer is what I imagine being in a gigantic soap bubble is like. Everything is vibrant and colorful, and you can often catch glimpses of a rainbow-like “shimmer” in the lighting. This area is simultaneously nightmarish and dreamlike, offering a world that, for better or worse, you will not be able to tear their eyes away from. The performances are also great, especially Portman, who plays the character with calculated restraint that devolves into brokenness and damage. The film is largely from her perspective, but she also has a good supporting cast around her, particularly Gina Rodriguez, Tessa Thompson and Oscar Isaac as Lena’s husband Kane. These other characters have some semblance of an arc, but they definitely could have been fleshed out more.

Outside of that, I have a lot of conflicting thoughts about “Annihilation.” For the first two acts, the story is very enthralling; Garland sets up personal stakes for Lena wanting to venture into this world, and he lays out all these different breadcrumbs as she journeys farther and farther into the Shimmer. It’s the third act that is going to lose a lot of people, and to be honest, I’m still going back and forth as to whether it lost me.

Throughout the movie, I was always waiting for the other shoe to drop, like there was some big moment that would resolve everything. What “Annihilation” does is, instead of dropping a shoe, it drops a sandal. The resolution of Lena’s journey is unlike anything I was prepared for, and after the film ended, it left me wondering for the next few hours what I had watched. I found myself thinking back through the movie, searching in my brain if there were other points in the film that suggested an ending like that. I turned to the internet, reading the Wikipedia plot summary and watching other reviewers discuss the film to see what they thought. “Annihilation” created this curiosity within me to understand what had happened, one I haven’t been able to satisfy.

The thing I watched that resonated the most was a (non-spoiler) interview with Alex Garland, in which he discussed the process behind making “Annihilation.” He said the thesis of it was the idea that all humans are self-destructive. This certainly makes sense, because the characters do overtly discuss the idea of self-destruction, but Garland also talked about how that self-destruction was meaningless. This struck me as odd, because don’t we all have at least some motivated reasoning behind why we do the things that we do? After he mentioned this though, I began to think back on the film, specifically Lena’s actions and her relationship with her husband, and how the Shimmer is, in some ways, a manifestation of these self-destructive struggles. There’s a lot of depth to be pulled from concepts like this, and I think Garland leaves this film intentionally open-ended because perhaps the nature of these events are meaningless and random — not unlike biological evolution itself.

“Annihilation” is definitely not a film for everyone. It leaves a lot of questions unanswered, and its conclusion is not entirely satisfying. That being said, I like when a film makes me think, and “Annihilation” certainly has that going for it. This will be a sci-fi film that people debate about for years to come, and I think for that reason alone, it’s worth taking a look at.