It's both tantalising and deliberately unsatisfying. You're never given the comfort of knowing what comes next.

While the result may not be quite as deep as the cavern at the centre of the story, it has an enticing sliver of ice at its heart.

A sterile, supercilious, derivative exercise in sub-Euro-arthouse ordeal. But there is no ordeal because nothing is at stake.

Masterfully slick, unsettling filmmaking builds this film into something more profound than it seems at first glance. It's one of these films that is going to be endlessly divisive just because it's so ambiguous and creepy.