Ruth Wilson gives a superb performance as a woman in her late thirties whose life is going nowhere. Lacking a partner, or even real friends, alienating her parents, she is lonely and unfulfilled.

She has a chance encounter with a strange but charismatic man and becomes obsessed with him. He alternately spends time with her and ignores her. I won't go into detail as it will spoil the way things unfold, but her neediness and sense of isolation are cleverly portrayed.

The rapid cuts, out-of focus shots and tuneless music get a bit irritating at times - presumably they are meant to show her confused state of mind.

At the end she achieves some kind of clarity about her life, shown by the camera-work becoming steady and focussed.

Powerful and haunting - well worth watching.