In a remote village in Northern Thailand a boy is run over by a truck just outside school. A local teacher, Sumaree, and her husband, Swedish Rex Roxenhed, engage in the case and start to investigate the company behind the heavy traffic. Meanwhile, the Police are preparing to strike against a local drug lord. Sumaree's attempt to look after her students safety suddenly coincide with the authorities fight on drugs. The resolution reaches its climax when an old love story unravels.

Blood Red River is set in a Thailand far beyond the tourist resorts and is a story about family ties, poverty and the daily struggle for survival, but also about lifelong love.