David Sloan, the last surviving brother, struggles to keep the family's Los Angeles kickboxing gym afloat with his business partner, Jack.

He offers free kickboxing lessons to local kids, often demonstrating a technique he calls the "rock and the river" which allows him to defend against attacks while blindfolded.

Although his will to compete has waned since the loss of his brothers, financial problems eventually force David to fight again in a new organization run by a crooked promoter, Justin Maciah.

While recovering in the hospital, David is visited by Xian Chow, the Muay Thai Kru who trained his brother Kurt in Thailand.

In a bloody bout reminiscent of the "ancient way" of fighting in Thailand, (using tape covered in resin and broken glass) David is beaten badly and has clouded vision.

When his students introduce him to the new neighborhood bully, David once again demonstrates the "rock and the river", but the lesson is cut short when the ice cream truck arrives, and Xian treats the kids.