John serves as a loving but neglectful dad to two troubled sons, sickly Tim (Devon Alan) and his restless older brother Chris (Billy Elliott's Jamie Bell), who keeps running afoul of the law. When John's ex-con brother Deel (Josh Lucas) unexpectedly arrives on the doorstep, he first seems a welcome presence, despite his predatory smile.
Undertow portrays two pairs of siblings by evoking fairy tale, myth and the Cain and Abel story. Shocking betrayals hang over John and Deel's relationship, while Chris proves fiercely protective of Tim, as if to show the extremes of brotherly ties. When Deel, who harbors long-standing grudges, quizzes the brothers about their father's hidden money, the boys begin to wonder if their dad's old story about family riches might be more than family legend.
Filmmaker David Gordon Green doesn't so much visit the Deep South as descend into it. He cultivates a mood of impending bloodshed, but by evoking Southern horror flicks and crime potboilers of the 1970s. Using natural light and shaky camera work, Undertow plays out like the bad dream you might have after watching a night of R-rated Burt Reynolds films like Deliverance or Gator.
When violence finally erupts, the film follows Chris and Tim as they flee into the wilderness and across some of Dixie's most impoverished locales, providing a cinema verite portrait of a hardscrabble way of life.
The suspense eventually leaches out of Undertow and the archetypes become increasingly artificial. Green's meditative narrative style -- first seen in his debut, George Washington -- uneasily fits the requirements of a chase thriller, even one as thoughtful as Undertow. But the film's third-act weaknesses don't diminish Undertow's powers at conjuring some of the raw sights, sounds -- and even smells -- of the South.