Nagasaki's gem centres on Kasumi (the superb Amami), whose life is transformed by the mysterious disappearance of five-year-old daughter Yuka while she and her husband are at a Hokkaido holiday park with another couple. Based on a novel by Natsuo Kirino, the film investigates how Kasumi came to be sleeping late when Yuka vanished, and its subsequent impact on her life. Of course, it also seeks an explanation for the disappearance. Guilt, grief, trust, doubt and recrimination come into play. The unfolding narrative produces subtle, even surprising twists, uncovering further levels of rich, relevant nuance, through which the film achieves a psychological and philosophical depth and complexity seldom found outside seriously good long novels. That's partly because the writer/director allows himself 201 minutes to explore the web of cause and effect that spreads backwards, forwards, even sideways from a life changing moment. Shooting on high definition video, Nagasaki keeps the story - flashbacks, fantasies, speculation - lucid and perfectly paced; from its riveting start to profoundly satisfying end, it grips like a vice.