US-indie maverick John Sayles' new picture is a kind of Tex-Mex reheat of his City Of Hope. There he used his novelist's eye to cross-cut a cast of Altmanic proportions, painting a picture of community imploding under the weight of its own expectation and prejudice. Lone Star uses as many performers, the same mosaic of storylines and makes a more than worthy sequel to one of the best American films of the 90s.

We are lured into all this through the auspices of a thriller: just outside Frontera, Texas two men have unearthed a corpse on the army rifle range. A rusted star and Masonic ring soon establish it as Charlie Wade, the corrupt, racist former sheriff who disappeared 40 years ago. A .45 slug implicates Buddy Deeds, Wade's well-respected successor and father to current sheriff, Sam (Chris Cooper). Sam's subsequent investigations gradually focus just how much his own and the town's present is informed - even dictated - by the legend and reality of his father.

A tale like this demands flashbacks, of course, but not for Sayles cut-ways or monochrome. Instead he avoids cutting altogether by the simple expedient of sliding his camera over incidental detail to deliver the film into the hands of the past. The results are disorienting, visually suggesting Sayles' argument that sometimes the now and then are inextricably linked. "Forget the Alamo," is the sign-off.

Borders like that are the second strand of this elegant script. In the same way that it suggests the boundary between the past and present is as much in perception as reality, so Sayles' screenplay examines the idea of borders in terms of the geographical, generational, economic, racial, cultural and political mix. It is to his credit that such heavy themes are engaged on such light and beguiling terms.

Sayles' cast are uniformly striking. Cooper, veteran of both City and the blistering Matewan, is terrific as a man set adrift in time, attempting to reconcile memories of his father with the town's rose-tinted nostalgia, and to rekindle a childhood romance his father broke-up years before. Joe Morton is the hard-ass black colonel assigned to a nearby fort that is about to close, who has to face the emotional challenges of both his son and his own father (Ron Canada, excellent). Contradictory C&W legend Kris Kristofferson turns in his best work since Peckinpah's Pat Garrett And Billy The Kid as the genuinely scary Wade, and Hollywood stud-muffin of choice Matthew McConaughey proves himself more than just a pretty face as Buddy. The excellent Frances McDormund also makes a notable cameo as Sam's estranged wife.

Cinematographer Stuart (The Piano) Dryburgh's widescreen shooting is beautiful but unfussy and, like Mason Daring's score, underpins the director's dissertation rather than shouts up for itself. Sayles' films have become progressively more stylish since Matewan but never at the expense of ambition.

After the well-meaning but fusty kiddie flick The Secret Of Roan Innish, and the likeable chamber soap-operatics of Passion Fish, Lone Star is Sayles back on firm ground. It is quietly funny, intricate, intelligent without it gets didactic or preachy, and above all humane (even the kicker of a final revelation is used to quietly subversive ends). A prime cut of American liberal cinema at its very best.