In 2001, 85,000 baby teeth were discovered in Missouri, collected 50 years earlier in a study on the radioactive consequences of nuclear testing conducted on US soil. Carried by the wind, radioactive material produced by more than 100 nuclear explosions contaminated pastures, vegetables and water across the continent. Scientists and mothers in St. Louis, who launched the ambitious project to measure Strontium 90 in baby teeth, uncovered the disturbing environmental consequences of nuclear arms testing. Featuring narration from Alec Baldwin, director Hideaki Ito unveils the shocking legacy of nuclear testing in the US and the ongoing policy decisions shaping our future.