Redundant and unnecessary.

I cannot think of one single thing that I would change about this film. The acting is incomparable, the directing deft, and the writing poignantly brilliant.

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."

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