Lan Xiao Yu, a mediocre lady from the capital, is always forced by her father to go on various blind dates, but she already has a place in her heart - she has always been secretly in love with the most handsome man in the capital, Prince Wei Qing. An accident caused her to exchange souls with Chi Jing Yu, the top assassin of the Qingluan Society, and Lan Xiao Yu became a peerless martial arts master. Instead of Chi Jing Yu, she sneaked into the Qingluan Society to investigate an assassination case...