A modern auditor time-travels to become Jiang Xu, a capital playboy, unexpectedly placing top in the imperial examinations and bearing the stigma of buying an official position for one hundred thousand liangs. He senses that his elder brother Jiang Chuan's fatal fall from a horse was no accident, but plotted by Prime Minister Shen Yuan. Using his playboy persona as camouflage for self-preservation, Jiang Xu relies on auditing skills to gather account books and physical evidence. Through court confrontations and life-or-death crises, he joins forces with Xie Tang to progressively tear apart Shen Yuan's conspiracy of embezzling military provisions and rigging the examinations, clearing his brother's wrongful grievance. After the case is settled, he is appointed to walk the six ministries, facing head-on the various political games at court, and discovers old secrets involving the emperor and princes from their youth.