In a village where the floods receded in 1978, a boy named Chen Xiaohe met his mysterious new neighbor Lin Xiaoou. This city girl who can fold strange paper boats and understands complex mathematics came to the village with her "sent-down" father. The two children established a secret base in the waterwheel house, but encountered suspicion in the "Missing Reed Chicken" incident. When Chen Xiaohe stepped forward to protect Lin Xiaoou, she discovered her father's hidden naval past and her mother's serious illness.
In this autumn full of prejudice, paper boats carry the innocent promises of two children: one wants to build a big ship to go to the sea, and the other wants to be a doctor and cure all people who have coughs. And on the riverbank washed by the flood, those exiled paper boats will eventually drift away with their most precious secrets...
