In the remote Linglong Village in the 1980s, a 12-year-old girl Lingzi was injured on her way to school. Her deaf-mute father Zhuzi was angry and sought revenge, which almost caused disaster. The village captain Lu Guozhi stopped her in time and was determined to seek justice for Lingzi. Fusheng fled in fear of crime, and his mother hanged herself out of guilt and self-blame, leaving her granddaughter Yanzi alone and helpless. This further strengthened Lu Guozhi's determination to pursue the murderer. He said goodbye to his family and went to the city alone. With no money, he relied on his car repair skills to repair the tribe's feet and transformed a scrapped tricycle into a "murder chariot". He worked hard to make a living while exploring Fusheng's traces. On the way to chase the murderer, Lu Guozhi always cared about Lingzi and Yanzi, and kept writing letters to enlighten the children. He also gained warmth and help from getting along with Master Zheng from the repair department and Hu Er, the tricycle driver. After months of running around, he finally found Fusheng. Faced with Fusheng who refused to admit his mistakes, Lu Guozhi persuaded people with reason and moved people with emotion, analyzing the faults and consequences of his actions layer by layer, and finally awakened Fusheng's conscience and made him voluntarily choose to plead guilty. This brought an end to the pain in the mountain village with both justice and warmth, and also protected the dignity of the child and the hearts of the village.
