On a stormy night, car owner Xue Cheng was seriously injured due to brake failure. Qin Shihai, the garage owner, shifted all blame onto technical supervisor Lu Yuan. He forged maintenance documents and tampered with surveillance footage. Lu Yuan stuck to his professional ethics and marked "Vehicle Not for Delivery", yet he was viciously attacked online. Thanks to his years-long habit of keeping complete records, he traced clues including accessory batches and codes of worn parts. Together with the car owner’s wife Shen Qinghe, he uncovered the truth. With key evidence such as collective complaints from drivers, abnormal insurance data and honest testimony from an apprentice, he exposed the garage’s scandal of replacing original parts with inferior substitutes. Lu Yuan cleared his name and founded a vehicle safety inspection center to uphold standards in auto repair.