It recounts the fabled tale of Di Renjie, a man renowned for his ability to solve crimes. Di Renjie is awaiting his formal appointment in Chang’an after passing the imperial exams. But Empress Wu Zetian abruptly sent him to a frontier village,

where he is confronted with a number of riddles. Di Renjie takes up the difficulty of maintaining the higher judiciary’s obligation to promote public peace and prosperity.