I tend to get very invested in any story structured as a descent, given, of course, that it’s well-executed. Films such as “Aguirre, the Wrath of God” and “Apocalypse Now” fall into this category for me, as both films depict a dark, foreboding descent into the unknown, as the madness of the environment slowly manifests itself in the voyagers themselves. This was one of the first things to grab me in Alex Garland’s newest film: “Annihilation.” Having previously enjoyed Garland’s “Ex Machina,” I was excited to see how the director would continue to broaden his horizons with this latest foray into science-fiction. In many ways, I was pleasantly surprised; in others, I was terribly disappointed.

Natalie Portman stars as Lena, a professor at Johns Hopkins University whose husband mysteriously returns home after a year of unexplained absence and becomes violently ill shortly thereafter. Lena later learns that this is a result of his last mission, which saw him enter an anomalous zone referred to as the “Shimmer.” An alien phenomena of unknown origin, the Shimmer is a colossal, iridescent dome which seems to rapidly mutate everything within its boundaries. Lena, desperate to remedy her husband’s condition, enters the Shimmer with a group of scientists in an attempt to decipher the enigma that lies at the region’s heart.

The film captures the feeling of a descent into madness (though the madness of this film is portrayed more through its environment than its characters) pretty well, and the escalating tension throughout kept me intensely involved through the film’s final act. Aside from the story’s premise, the structure of it also worked quite well for the most part, as interspersed between the action are scenes of Lena being interrogated as to what exactly she encountered within the Shimmer, and how she interpreted what she saw. I was reminded of David Fincher’s “The Social Network” in this regard, and although this didn’t make as clever use of it as that film did, it still managed to add an extra dimension to the film, which I appreciated.

What really ended up weighing down the film for me, though, was the flat dialogue and wholly uninteresting, lifeless, vapid characters. See, this film suffers from something I call Prometheus syndrome. For those of you who are unaware, Ridley Scott’s 2012 film “Prometheus” actually suffered from many of the things I just mentioned. Much like “Annihilation,” “Prometheus” features a lot of awe-inspiring visuals and engrossing ideas, but its lifeless characters and idiotic writing hold the film back from becoming anything more than “alright.” Who could forget such great characters as the navigator who becomes almost immediately lost, or the woman who runs from a slowly falling object whilst remaining in its direct trajectory the entire time, never once thinking to sprint slightly to the left or right and avoid death.

“Annihilation” features many such mind-numbingly stupid moments. One such frustrating example involves a character who witnesses a video recording of a man being cut open, only to reveal that his intestines have begun to move of their own volition. She immediately closes the video camera, and claims that it must have been a “trick of the light.” Excuse me, what? It was very, very, obvious what was just seen, and she dismisses it just like that? These people are supposed to be medical and scientific professionals, right? I understand that she’s meant to be in denial of what she’s just witnessed, but this scene seemed to be very poorly handled. Another scene sees the group have a close encounter with some manner of mutated boar-like creature, which simply walks around them in circles, screams at them a bit, and leaves. Why, though? We’ve seen this thing rip people apart in previous scenes, and it’s just gone docile here, for the sake of the plot? Again, another poorly handled, nonsensical scene; perhaps its vision is based on movement.

Let’s go back to something I just mentioned, as well. That bit about them being medical and scientific professionals. Actually, if I recall correctly, one of them was fresh out of college and had only been at the facility for two months. Wait, does this mean that they then had only two months of training for this mission? Can they even adequately manage a firearm? Why not send in some soldiers to escort these scientists? They do mention that the previous groups they sent in were comprised entirely of soldiers, none of which returned. Still, if they’re that content with sending people on these suicide missions, and they’re looking to send people in who have a more scientific perspective, why would they send in the group of scientists without an escort? When at least one of them, possibly all of them, have only rudimentary training? Wait, I get it. They’ve all got nothing to lose, right? One of them has a husband on his deathbed, one of them has cancer, one of them is suicidal, etc. Wait, that’s even worse! A mission of this gravity and they’re all mentally unstable? Is this really a good idea? The more I thought about all of this, the more flashbacks I had to “Prometheus,” and it’s a real shame that a film with such interesting visuals and concepts had to be bogged down by such carelessness.

What saved the film for me, though, was its incredibly strong final act. I’ll say first that it’s not as if the film’s characters really needed to be developed or particularly interesting (sci-fi films such as “2001: A Space Odyssey” never needed this, as HAL is the sole character focus of the film, nor did “Stalker,” as its characters are pure allegory), but when the film is so occupied with spending time with them, showing us their conversations, showing us Lena’s past life, and so on, you’d expect that we end up interested in some of the characters at least a little bit. It didn’t help that most of the acting was extremely bland, and in some cases, unconvincing. This, funnily enough, is one of the reasons why the final act of the film is so strong. Since all but one of the characters are either missing or dead, the film isn’t being held back by any of that. The sound design of the film becomes unexpectedly strong during this sequence as well, a welcome departure from some of the seemingly uninspired soundscapes of the film’s earlier scenes. The entire set of scenes that take place at the heart of the Shimmer are absolutely mesmerizing, and although many of the events that take place there are incredibly ambiguous, I actually didn’t particularly mind that. Much like the famous ending sequence of “2001: A Space Odyssey,” the film seemed to trade definite form for pure awe and evocativeness, which is a daring move, but again, I feel it worked in the film’s favor here.

Thus far, I’ve said a lot of good of this film, and I’ve said a lot of bad. Assigning this film a star rating is a daunting task for me, because, in spite of its many failures, I also consider the fact that the film was able to pull me back in the end and hold onto me so tightly until the credits to be a great achievement. Still, I don’t feel that I can give the film any higher than I decided upon rating, taking into account everything I’ve said. So, take this rating with a grain of salt, because there is a lot here to be enjoyed, and I’d still recommend you check it out if only to see what you make of its dazzling final sequence. Brando’s rating? Two-and-a-half out of four stars.