Jiang He, a female shop owner, struggles to keep her father's auto repair shop running on her own. Bullied by competitors and squeezed by chain stores slashing prices, she is on the verge of losing the shop. One day, a down-and-out man arrives with his daughter, offering to work in exchange for a meal. Who would have guessed that his ears are sharper than any machine? He can pinpoint an abnormal idle noise just by listening, detect dragging brakes by their smell, and fix a refrigerated truck in ten minutes. He was once a top technician at a 4S dealership in the provincial capital, but a customer complaint drove him to a small town. Two single-parent families come together under one repair shop's roof. With transparent repairs and publicly disclosed prices, they take on a chain-store giant and use their technical skills to prove the entire street wrong. But his past is far more dangerous than auto repair.