Li Shoushan, a retired master auto mechanic, is lured back to save a nearly bankrupt repair shop by his own nephew, Wang Haoyu, who appeals to family ties and promises him a 30% share of the profits. With his exceptional skills, Li brings the shop back from the brink and helps it earn tens of millions a year, only to be cast aside, cheated out of his earnings, and humiliated by his nephew. After seeing the cold-heartedness of his own family, Li finally awakens when his household falls into hardship. He mortgages his property to start his own business and launches a desperate commercial revenge against his treacherous nephew, armed with nothing but his formidable craftsmanship.