The initially imposing sci-fi drama Sunshine is actually pretty simple, once you get down to it: Boil away the artful special effects and the futuristic technobabble, and you'll find the reliable, familiar theme of man against nature. The catch, here, is that "man" is a team of smarty-pants scientists, and "nature" is the unforgiving sun, which looms over our protagonists, threatening, at every moment, to incinerate each of them into nothing more than a cloud of white-hot molecules.

The latest from director Danny Boyle and screenwriter Alex Garland (who previously collaborated on the mostly awesome 28 Days Later and the pretty crappy The Beach), Sunshine takes place 50 years from now, with a barren Earth frozen by a solar winter: The sun is dying, and humanity finds itself staring down a cold, dark death. Humanity has just one plan, and it is desperate and flawed: Loading a huge bomb onto a spaceship, the Icarus II, a small team of scientists will attempt to jumpstart the sun.

To give away more of the plot would be a disservice; suffice to say that (A) things go wrong, and (B) Boyle and Garland use their relatively simple concept to delve into themes ranging from religion to sanity to sacrifice. But mostly, Sunshine is a tense, drawn-out thriller—much of the film is spent watching characters face horrible, impossible situations, and the rest is spent watching them live with the aftermath of their decisions. Boyle is patient and clever, and it all plays out with a sense of both inexorable doom and dumb hope. None of this would work without Sunshine's solid cast, led by the always-excellent Cillian Murphy and featuring sharp performances from Rose Byrne and Chris Evans.

Sunshine's not perfect: For a weird spell in the third act, Boyle decides to try out his skills as a horror director—briefly but effectively morphing Sunshine from a smart sci-fi thriller into a dumb teen slasher flick. But that's a brief blemish on an otherwise impressive, gorgeous, and nerve-wracking film.