Synopsis：Song Yun was born in a family of doctors. Her elder sister Song Zhi was the best female doctor in the palace. However, the jealous imperial concubine tortured Song Zhi to death and executed all the members of the Song family just because of the emperor's praise. Song Yun did not choose to live in hiding. She hid her identity and became a maid beside the imperial concubine. She calculated every step and was good at poisoning. She finally killed the imperial concubine and brought justice to the Song family and the prosperous and peaceful times.