Prolific Hong Kong film-maker Herman Yau is back with an ambitious, sprawling drama that is, at best, an awkward composite of his past works. We’re Nothing at All kicks off with a moment of rupture: on a seemingly ordinary Valentine’s Day in Hong Kong, a double-decker bus suddenly bursts into flames. The deadly explosion triggers a police inquiry led by Lung (Patrick Tam), a skilled forensics specialist whose investigation reveals a maze of intersecting lives. Much like the volatile opening, the rest of the film luxuriates in paradoxes, where the facade of normalcy is peeled back to reveal poverty, prejudice and despair.

From inspecting the charred bodies of the victims – rendered in lurid closeup – to retracing CCTV footage, Lung’s gathering of clues is crosscut with flashbacks concerning those involved in the explosion. Among the dead are lovers Fai and Ike (played by pop stars Anson Kong and Ansonbean), gay men who have endured economic hardship and family rejection. With its golden hues, the warmth of their intimacy starkly contrasts with Lung’s world of colourless offices and sterile meetings. The juxtaposition is visually fascinating, yet the twin narratives of a police procedural and queer romance are strained, resulting in tonal disorientation.

Despite working within the framework of mainstream cinema, Yau does sneak in subtle political commentary. A brief scene in which a man angrily reacts to a government official’s speech slyly echoes the protests that gripped the island in 2019 and 2020. Still, it is hard to overlook how poorly written the gay characters are, with queer lives reduced to simplistic archetypes: noble sex workers, traumatised victims, suicidal youngsters. With no real inner lives, these characters are blank canvases on which social turmoil is projected. Far from subverting ongoing discrimination, this misstep renders the whole film woefully obtuse.

• We’re Nothing at All is in UK cinemas from 29 May.