Good story, Not enough for a whole film

If the ambition is to provide two hours of instantly forgettable, popcorn-munching escapism, it succeeds.

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."