It's hard to see any effort in the film. There's no comedy to speak of, no real drama and, worst of all.

I cannot think of one single thing that I would change about this film. The acting is incomparable, the directing deft, and the writing poignantly brilliant.

It's funny, it's tense, it features two great performances from two actors and the director expertly creates a web of odd tension where you actually don't know what is happening for the majority of the run time.

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