Zhao Tiesheng, a veteran repairman, spends all his savings helping his son, only to be humiliated by his daughter-in-law and thrown out of the house at a birthday banquet. Left homeless, he turns his extraordinary ability to diagnose faults by listening to sounds into a thriving business, rising from nothing to become a sensation. His ungrateful son and family grow jealous and repeatedly come to leech off him. Zhao livestreams to prove his innocence and repairs everything from luxury cars to heavy machinery. He can fix countless machines, but mending human hearts is the hardest job of all.