“Danger: High Voltage” are among the first words seen on screen in writer-director Clement Virgo’s adaptation of David Chariandy’s 2017 novel. It begins with wannabe DJ/producer Francis (Aaron Pierre) pressuring his younger sibling Michael (Lamar Johnson) to join him in scaling a sinisterly buzzing pylon in their home town of Scarborough, Ontario. The voltage stays at that level throughout much of Brother, which ticks off several films’ worth of heavy-duty subjects – police brutality, racism, the immigrant experience, gang violence, closeted desire, dementia, cancer – and only occasionally verges on the ponderous. The question that haunts the film is: what made Francis climb that day? After the opening scene, the action shifts forward a decade to find Michael, his old flame Aisha (Kiana Madeira) and his mentally fragile mother Ruth (Marsha Stephanie Blake) still reeling from Francis’s death. In dealing with the tensions and pressures of Black masculinity, and slipping between three separate time periods in the life of its fatherless protagonist, the movie inevitably invites comparison with Moonlight. Memories of that Oscar-winner are also summoned by Todor Kobakov’s dolorous score and Guy Godfree’s cinematography, which is so sumptuously lit that it almost stains the eyes. Heavy with grief the film may be, but it’s always a beautiful mourning. Brother’s best hopes of escaping Moonlight’s shadow lie in its textured portrait of the Jamaican-Canadian community, an approach to violence that achieves maximum impact from minimal detail, and its nuanced performances. London-born Pierre brings the same mix of charged intensity and choirboy sweetness that made him so compelling in The Underground Railroad, while Madeira breathes life into a character who is essentially the film’s conscience; her speech about the burdens placed on immigrant parents is delivered with casual flair. It’s Johnson who drives the film, though, expertly conveying Michael’s transition from teenager to adult, his youthful twitchiness hardening into a guarded and fearful remoteness. A few minor plot surprises give the rug beneath our feet a gentle tug, even if they never quite pull it from under us. And it’s not hard to see how the film could be strengthened: fewer plaintive cellos on the score might lessen the impression of a calculated assault on the tear ducts, and a more sparing use of atmospheric slow-motion would shave minutes off the running time. As with Francis, though, Brother is still an example of strengths outnumbering flaws. Brother is in UK cinemas and on Curzon Home Cinema from 15 September