Blending excellent reporting and strong storytelling, this is a disturbing film truly stranger than fiction

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."

After playing with our expectations, this turns out to be a very different sort of film.

Each character in this movie — down to the smallest one — is an individual rather than a type, prone to spontaneous changes of mood and sometimes amusing outbursts of pettiness or ill humor.