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."

This is one of the few movies I've ever seen where the whole audience broke into spontaneous, loud applause a third of the way in.

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

Unshakable, witty and deeply felt, the film will be paying emotional dividends for a long, long time.