There’s the skeleton of something really intriguing in this Cantonese-language Hong Kong drama about a father (Sean Lau) wrestling with survivor’s guilt and grief after the murder of his wife and young daughter at the hands of his mentally ill teenage son. There’s a powerful early scene set on the morning immediately after the tragedy when Yuen, unsure what else to do, goes to work as usual and is met by the stricken, anguished stares of his friends and neighbours. It’s an elegantly staged and genuinely uncomfortable moment. But then the promise of the film is soon buried beneath layers of flabby backstory and numerous unwieldy flashbacks. And the film turns from being a psychologically astute account of dealing with the aftermath of unimaginable trauma to a ghoulish countdown to the attack itself. A wasted opportunity.

• In UK and Irish cinemas