While it doesn't offer any answers, it both thrills and makes you think.

It's the kind of movie you'll want to see a second time with someone who hasn't seen it yet, to remember what it was like to watch it for the first time.

It is neither dumb nor smart enough to be fun, and spends way too much time with its boring human characters.

The film never slows down or bores, plunging from one harrowing sequence to the next.