John Singleton’s contemporary urban gun-slinger incorporates a western-style vigilante theme to mostly agreeable effect. The four eponymous siblings were adopted as delinquent kids by tough-talking foster mum Evelyn Mercer (Fionnula Flanagan). Her time on screen is shortlived; she is gunned down in a grocery store after giving a shoplifting teen a stiff but kind-hearted lecture on social behaviour. Singleton presumably slipped in this brief pre-killing sequence to drum home the reason why her disparate sons – two black, two white – have managed to stay so firmly on the straight and narrow. But now she’s gone and all four Mercer brothers – irascible ex-boxer Bobby (Mark Wahlberg), womanising dude Angel (South Central rapper Tyrese Gibson), young rockstar wannabe Jack (Garrett Hedlund) and businessman Jeremiah (André Benjamin of eccentric pop duo OutKast) – have returned to Detroit armed with a hatful of questions and revenge on their minds. A quarter way through, the film switches from a likeable character-led study on family ties – that sees the boys revisiting their home for the funeral and exchanging enjoyably mundane reminiscences around the Thanksgiving table – to a slice of visceral urban warfare with caricature baddies, big guns and loud bangs. Credit to Singleton; he rarely loses sight of the human drama side of things, bathing it all in an urban silvery hue and garnishing it with a stimulating soundtrack. A shame, then, that the film’s dogged by too many anomalies and loose ends and, in the end, by a lack of tension. Some select turns, though, especially from Benjamin, who sports a set of teeth like a row of luxury hotels on the Florida coast.