Natalie Portman headlines as Lena, a biologist whose husband (Oscar Isaac, in what nerds will identify as a "Star Wars" cross-trilogy marriage) has gone missing on a military mission. It turns out that he had disappeared into something called The Shimmer, a strange, perhaps alien expanse — ensconced within what's known as Area X — that's slowly but inexorably growing, threatening the world along with it.Adapted from Jeff VanderMeer's book (and already the subject of some controversy amid charges of "whitewashing" in its casting), "Annihilation" is a notably female-centric film, as Lena embarks on her expedition into The Shimmer with an all-women group, well aware that it's a bit like an ethereal roach motel — researchers go in, but they haven't come out.In its tone and stylized look, "Annihilation" brings to mind "Arrival," another recent science-fiction film that dabbled in big ideas. But unlike that movie, Garland — who made an impressive debut with "Ex Machina," also co-starring Isaac — can't muster the same level of emotional resonance, despite a framing device that flashes back to Lena's life before all this began.Fortunately, Lena takes an intriguing bunch with her, joining specialists in various fields played by Gina Rodriguez, Tessa Thompson, Jennifer Jason Leigh and Tuva Novotny. The bizarre landscape they must navigate — trying to reach the point where The Shimmer originated, and thus unlock some answers — is fraught with peril, creating an odd sense of tension, leavened by occasional moments of dark humor thanks to the sheer absurdity of the obstacles they encounter.The timing surely feels right for this sort of female-led enterprise. What's lacking, perhaps inevitably, is a well-articulated grasp of the threat, as Garland settles for a sort of on-the-fly tutorial in the microbiological underpinnings of what might be happening. Through it all, Portman is tough, pained and emotionally numbed, desperate for answers but also seeking redemption for reasons that finally become clearer, frankly, than almost anything else in the movie.There's nothing wrong, obviously, with science fiction that isn't spoon-fed to the audience, a half-century after Stanley Kubrick demonstrated that with "2001: A Space Odyssey." "Annihilation" certainly dares to be cryptic, and for most of the trip, has the audience on edge. Ultimately, though, when your movie is built around deciphering an apocalyptic threat, it would be nice to leave feeling like you know more than you did when you first sat down.Broken down to the basics, Garland has delivered another movie that's worth seeing. Like the Olympics, though, even when you put together a beautiful routine, points get deducted when you slip on the landing."Annihilation" premieres Feb. 23 in the US It's rated R.