Based on a true story, this film follows a 7-year-old boy, Wawa, and his older sister, Naxiang, who live beside the Nujiang River in Yunnan Province, China. Every day, Naxiang crosses the river to attend school using an overhead cable, but their mother will not allow Wawa to use the cable. Eventually, Wawa secretly uses the cable to cross to the other side. The dangerous activity has deadly consequences, and the siblings’ lives are changed forever.