Ann Hui returns to the infamous new town of Tin Shui Wai, the setting of her award-winning previous film, The Way We Are, for her latest outing. Deliberately named in reference to Alain Resnais’ 1955 documentary about Nazi concentration camps, Night and Fog is a powerfully acted, and at times harrowing, retelling of a recent true case of domestic violence and murder.

It is giving nothing away to reveal that young mother Hiu-Ling (played by Zhang Jingchu of The Beast Stalker) and her twin daughters are brutally murdered by her husband, Sam (Simon Yam). The film establishes this in its opening moments and the bulk of the narrative is told in flashback through a number of police statements given by neighbours and other young women from the women’s refuge where Hiu-Ling repeatedly seeks shelter.

The film backtracks to explore the events that lead up to, and may have provoked, such a gruesome crime. It also attempts, with little success, to understand the kind of man capable of murdering his own wife and children. It is not a failing of the film, however, that more answers are not gleaned from this path of investigation, but rather a realization that the motives of the film’s antagonist are largely beyond comprehension.

Hui does succeed in exposing the unique and rather eccentric relationship that exists between Hong Kong and Mainland China. It appears that for many in China, the perception of Hong Kong is of a gilded paradise, an economic haven where the streets are paved with gold and anyone can find their fortune. When Hiu-Ling brings Sam back to her village, her parents are quick to look beyond the sizeable age difference, his volatile temperament or even the way he looks at their younger daughter. What they see is a man from Hong Kong and, not far beyond that, a steady source of income to see them through their twilight years. Sadly, the well being of their daughter scarcely enters into the equation and by this time the audience are already well aware of what fate awaits her.

At the receiving end of this by all accounts commonplace scenario is a steady influx of young Mainland wives into Hong Kong, who are often subsequently neglected by their supposed benefactors to varying degrees, if not mistreated or abandoned completely. Hiu-Ling finds herself on more than one occasion seeking shelter at the local government-run refuge, where conditions are poor, supplies are scarce and the presence of licensed and qualified doctors and careworkers is pitifully infrequent. Hui stops short of claiming Hiu-Ling’s blood is on their hands, but only just.

Hui’s fly-on-the-wall, almost documentary feel adds a layer of realism to the unfolding drama, deliberately accentuating the shortcomings of a system ill-equipped to deal with these problems in an oft-neglected district. That said, Hui is a skilled enough filmmaker to know that these circumstances alone do not make for an engaging drama. The Rashomon-style structure, where facts are uncovered piecemeal and out of chronology through the testimonies of unreliable witnesses, serves to highlight the inconsistencies in such cases, conceding that it is no easy problem for the authorities to tackle. Domestic abuse is often difficult to prove and even harder to prosecute. It is not uncommon to live a scant few feet from our neighbours, possibly for years, and still know nothing about who they are or what goes on behind their closed doors.

Simon Yam proves once again that he can play down-at-heel working-class with shocking effectiveness and that he can also be genuinely terrifying. Zhang is only too believable as the frail, naïve and long-suffering Hiu-Ling who lives under a constant cloud of threat and torment. Their relationship is built on fear and the threat of violence and the audience can’t help but experience Night and Fog in the same nervous manner. It is a film to be admired and respected, rather than enjoyed. It is difficult viewing, yet in highlighting such a tragic story unravelling within a larger social issue to which many in Hong Kong are oblivious, it might also be essential. James Marsh