Ben Whishaw stars in Hong Khaou's touching English language debut about sexuality and acceptance

Words sit at the heart of Lilting – things unsaid, conversations missed, meanings garbled – and for Cambodian director Hong Khaou, this debut feature revolves around the essential nature of communication.

Khaou's film is a deeply intimate one, anchored in the passions, and heartbreak, of human love, something both universal and open to endless interpretation. That the elegant narrative is driven by the search for understanding between people sharing next to nothing in common, thrown together only by their mutual connection, renders its touching conclusion all the more satisfying.

A refined blend of adult drama and cultural displacement, Lilting is a masterfully constructed tale, tying together its disparate, ethereal parts into something both unexpectedly moving and quietly accomplished. If Khaou can produce such maturity in a language other than his own, then his creative future seems rosy indeed.

He is fortunate to benefit from a superb leading duo of Ben Whishaw and Cheng Pei-pei, an oddly matched pair who spark off each other in a variety of unexpected ways. The captivating Whishaw plays Richard, a gay man living in London who is mourning the loss of his late partner Kai.

Their relationship is only ever depicted as a spectral abstract – half daydream, half flashback – but it certainly appears to have been a strong one. Richard’s tender longing is palpable, yet finely suppressed in a stiff-upper-British-lip sort of way, leaking out, on occasion, in choked sobs and sharp spikes of stifled rage.

Seeking to soothe his own pain and to do right by Kai, he reaches out to Junn (Pei-pei), Kai’s mother. The miserable resident of a comfortable, if dull, drizzle-enveloped retirement home, she exists in a world alien to her native Vietnam. Junn only speaks Vietnamese and the Chinese dialects, thus their progress is stilted immediately.

Unfortunately, Junn dislikes Richard anyway. Unaware of her son’s sexuality, she views his ‘friend’ as an irritating presence responsible, indirectly, for her quasi-incarceration. In an attempt to make life easier, Richard wishes to break down the spoken barriers sealing her off from the other residents, particularly Peter Bowles’s affectionate old gent, Brian.

He hires Vann, a spirited young woman who can speak any number of Junn’s languages, and she becomes the vital cog in the film’s burgeoning relationships. Vann’s role is more than a simple vessel, of course. As the bridge between two worlds, she must screen what Junn is told and what she will accept. This dichotomy of truth and culture is never more pronounced than when the subject of Kai is discussed.

Only ever glimpsed outside of the present reality Kai’s death serves as Khaou’s seminal event. It compounded Junn’s frustration at her own situation, one which has built since the moment she arrived in England. Years later, now a widow robbed of her only child, she has still not assimilated and her stubborn refusal to do so fuels Richard’s annoyance.

Pei-pei excels in portraying, as sympathetic, a lost woman barely thankful for the efforts being made on her behalf. Stoic and scornful, the veteran Chinese actress draws on a well of confused anger. Indeed, only her imaginary conversations with Kai (a beautifully conceived opening exchange stands out) allow for greater insight; she is free in her own mind to say the things she cannot master outside of it.

The tension in her dealings with Richard are deliciously tangible but Khaou, working from his own script, does not mine their subtle conflict for long. Instead, he builds a level of trust and respect between them. The younger man’s gestures are, eventually, well received but it is in the delicate details that he and Junn find each other.

From the traces of her son in Richard’s bedroom to his use of chopsticks in frying bacon, the intimacy of Kai’s influence on this stranger’s life is a reminder that he is more than a joyous figment of her present subconscious.

If there is one flaw, it is the insertion of an incredibly awkward romantic arc between Junn and the aforementioned Alan. Khaou aims for laughs and while one scene centred on the couple’s frank assessments of their mutual faults is amusing, the rest serves as an anomalous distraction in the otherwise fascinating story.

If the young filmmaker was trying to flesh out the brief running time, he was not altogether successful but, such quibbles aside, the remainder does more than enough to encourage us all to say what we must, while we’re still here.

Lilting runs at Queen’s Film Theatre, Belfast until August 21.