The "gag" behind John Singleton's Four Brothers is that two white cats and two black cats are brothers. As played by Mark Wahlberg, Tyrese Gibson, Andre Benjamin, and Garrett Hedlund, the title characters are rough-and-tumble hoods who mask their feelings with bravado, but care deeply about family, which is in itself another source of the film's bad (momma's) boy humor.
The adoptive brothers reunite to find out who killed Mom, a kindly old salt played by Fionnula Flanagan. Mom placed orphans in the Detroit hood, but as explained by Terrence Howard's cop, she kept "four delinquents so far gone that she couldn't find anyone to take them in." Bobby (Mark Wahlberg) most lives up to his rep, having only recently exited prison. Angel (Tyrese Gibson) is the playa who's whipped by his chica (Sofia Vergara). Jack (Garrett Hedlund) is the baby-faced slacker who assumes rock-stardom is inevitable. Jeremiah (Andre Benjamin) has a wife, kids, and a business plan, all of which single him out for paranoid suspicion.
Singleton's mostly interested in meting out reckless, anti-heroic vigilante justice, which explains why Singelton thinks of Four Brothers as a kind of urban western. Gun battles, a steady stream of wise-ass remarks, attack dogs, police corruption, and an exciting car chase in a blizzard ensure that Four Brothers may be a lot of things, but it's never boring. Josh Charles is miscast as Howard's partner, but the brothers have good chemistry, and Chiwetel Ejiofor happily chews scenery as the boys' crime-lord nemesis (he gets the film's best line: "I wrote the fucking book on finesse"). Singleton may go for easy laughs, but he gets them; the gut-level jolts may be ridiculous, but he delivers them (with style). Call Four Brothers a guilty pleasure.