The protagonist Su Chen travels to the Qin Dynasty in the troubled times, where the princes are divided, foreign enemies are around, and the people are in dire straits. He was originally a lowly horse slave at the lowest level of the Imperial City of Qin. He didn't even have a name, only the number "Horse Slave Seventy-Three." At the beginning, Su Jingming, the legitimate son of the Hou Mansion, whipped him with a riding crop in public and forced him to repair the abandoned racecourse that had collapsed for thirty years. He was given a one-month deadline, otherwise he would be buried alive.
