It's a mild crowd pleaser for people who are exhausted by blockbusters.

Tells a fascinating and unsettling true story, and does so well, without pretending to have all the answers.

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."

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