Mechanical repairman Han Tiesheng relies on a copper-core listening hammer, superior hearing, and practical craftsmanship to discover hidden equipment flaws that precision instruments fail to detect. After repairing an imported shield machine, his credit is usurped by the factory director and his son, leaving him with only ten yuan and a steamed bun, prompting his angry departure. From then on, Han Tiesheng forms the Divine Work Mechanical Repair Team, successively overcoming heavy difficulties such as military hydraulic presses, domestic shield machines, deep-sea tunnels, plateau permafrost projects, and aero-engine gas turbines, repeatedly smashing foreign technological blockades and comprador conspiracies. Faced with the temptation of huge foreign patent acquisitions, he chooses to dedicate all core technology to the country, forging the great national heavy equipment with the power of a craftsman.