"Sunshine" is set just 50 years into the future. At this point, the sun is dying so Earth has been thrust into a new ice age. A group of scientists, towing a nuclear weapon the size of Manhattan, are on a quest to deliver the payload into the sun, effectively reigniting it. Along the way, though, our intrepid crew (populated with a wonderfully multi-cultural cast that includes Cillian Murphy, Chris Evans, Michelle Yeoh, Rose Byrne, Hiroyuki Sanada, Cliff Curtis and Benedict Wong) investigate what happened to the first such vessel that attempted this voyage and may be fighting with the psychological effects of being so close to the sun. Just keep in mind, especially based on that description, whatever you think "Sunshine" is going to be; it's not.

Most of this has to do with Alex Garland's ingenious script. Garland had teamed with Boyle before; his novel "The Beach" was adapted by the director and Garland provided the script for their zombie refresh "28 Days Later." But this was something new and different, it was much bigger than either of them had imagined; it took a full year to refine the script and another whole year to complete editing and visual effects.

Eventually, the two creative principles ended up taking very difference stances on what the movie meant, to the point that it drove a wedge between them (they never worked together again). Whatever philosophical jousting went on behind the scenes, that creative friction did wonders for the movie. This is a movie that, like all of Boyle's films, feels very vital and alive in a way that few manufactured pop confections that flood the marketplace in the summer months do.

Part of that has to do with the streamlined nature of the film, which owes a debt to everything from "Alien" to "2001," with Boyle and Garland chopping away extraneous romantic subplots and unnecessary dialogue. This is a movie where everything feeds into the propulsive nature of the central narrative. And as much as the movie harkens back to classic science-fiction tales of old, it is unlike anything that has come before it (or since).

Now, let us talk, in veiled terms (of course) about the controversial third act.

Now, everybody loves to talk about a big twist. There are endless think pieces written about great twists; they inspire fierce water cooler conversations and ignite debate. (Just the other day, I was at a local fast food joint and overheard a conversation about who, exactly, Zendaya is playing in "Spider-Man: Homecoming.") In "Sunshine," the third act takes a wild left turn that will either leave you exhilarated or bewildered.

While programming a block of movies on British satellite channel Sky, Quentin Tarantino chose the film before calling its climax a "creative nosedive." "The third act tumbling goes far beyond disappointment. The feeling I experienced was betrayal," Tarantino said. "It goes against every aspect of that film's aesthetic that preceded it." Beyond an incredibly lengthy (shocking!) Reddit post, there aren't that many defenders of the last third of "Sunshine."

But that's okay.

One, it's a movie that will get you talking. How many current sci-fi blockbusters can you even muster a sentence about? How many just leave you blubbering puddles of goo, after being beaten into submission by two plus hours of nonstop visual effects insanity? So the fact that the ending of "Sunshine" will make you talk is wonderful. Tarantino even admits that the first two acts of the film are so good that no matter how disastrous you think the third act might be, it still doesn't lessen the film's impact (this is also true). And something that people just aren't owning up to: the third act is actually pretty cool. I'm hesitant to talk about just how the movie transforms, but patient and open-minded viewers will be rewarded for sure.

My suggestion: crank up the air conditioning, pull down the blinds, and get lost in the world of "Sunshine."