FILM-making brothers Jay and Mark Duplass, two key exponents of the low-budget mumblecore movement, err dangerously close to the mainstream with this quirky comedy of ill manners.

Like their previous work, Jeff, Who Lives At Home is distinguished by flowing, naturalistic dialogue and winning performances from an impressive ensemble cast.

Jason Segel and Ed Helms are extremely well matched as brothers from opposite ends of a shallow gene pool, whose humdrum lives are devoid of excitement and meaning.

Neither man is willing to confront the regret that wafts off them like cheap cologne, until a bizarre series of events unexpectedly shepherds the siblings to a life-or-death crossroads.

Ordinary men are capable of extraordinary feats, when they put their simple, addled minds to it.

Thirtysomething layabout Jeff (Segel) lives in the basement of his mother’s home, where he rhapsodises about the Mel Gibson sci-fi thriller Signs.

“I can’t help but wonder about my fate, my destiny,” he ponders aloud, convinced that the universe has big plans for him.

Until then, Jeff will happily moulder in the basement, throwing a tantrum like a truculent teenager when his mother Sharon (Susan Sarandon) has the temerity to ask him to get some milk from the local convenience store.

A wrong caller asking for someone called Kevin sparks Jeff’s febrile imagination and the waster becomes convinced that the enigmatic Kevin is going to play a pivotal role in his future.