Dentist David Kennedy travels to China with his wife Betty at the invitation of Shenyang Medical School to document villages crippled by naturally occurring fluoride in well water. The camera shows adults bent and immobilized by skeletal fluorosis, many disabled by their forties, and children with mottled, pitted teeth from dental fluorosis. Chinese researchers G. Hongxin and G. Dai had traced the damage across more than 1,000 counties in 28 provinces, estimating 25 million people affected by dental fluorosis and 1.25 million by skeletal fluorosis. The film follows a de-fluoridation program that cut water levels to 0.5-1.0 ppm, easing pain and improving mobility in adults, though bone and enamel damage proved permanent, and 37.8% of children in one village still developed visible fluorosis at just 1 ppm. Kennedy, past president of the International Academy of Oral Medicine and Toxicology, narrates throughout, and the footage of affected villagers is graphic. The film also notes fluorosis linked to airborne emissions from coal plants, though the cases shown here trace entirely to drinking water.