Setsuko Thurlow was 13 when the atomic bomb was dropped on Hiroshima. Horrific scenes of pain and destruction were burned into her memory. She moved to the US and Canada and began to tell the world what had happened in Hiroshima. Her work with the International Campaign to Abolish Nuclear Weapons (ICAN) overcame resistance from nuclear powers and resulted in the adoption of a UN treaty to ban nuclear weapons. Their efforts earned the group the Nobel Peace Prize. This gripping documentary follows Setsuko's journey from a childhood wracked by war to international recognition.