A film with more than the usual spoiler issues. Talking about it in any detail feels akin to handing you a gift-wrapped present and saying, "I hope you like it -- It's a thriller about a diabolical secret experiment."

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.

Just intense enough to provide a much-needed diversion, just lightweight enough to make you forget about it soon after it’s over. It’s not exactly “good,” per se, but it does what it sets out to do in terms of putting us on edge, which makes it … successful?

Strong acting helps the film overcome an uncertain premise and create characters that hold our attention absolutely.