The performances transcend the film's tropes, grounding it in characters that feel more complete than this subgenre often produces.

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.

The film's masterful storytelling did its job. The message was clear. No need to overdo.