Shangguan Wan'er, the legitimate daughter of the prime minister's manor, returns to the capital from the mountains, operating a stall in the West Market under the alias "Qingyun". A warning regarding a startled horse is fulfilled right on the street, making her the object of everyone's requests for help and drawing the attention of Xiao Jingyuan, the second young master of the Prince Wing's manor. From mutual probing to investigating cases together, the two successively uncover secrets of human trafficking, extortion, and the seizure of fortunes. While her family single-mindedly protects her to keep her away from trouble, she discovers that the consecutive perils faced by commoners and nobles are no coincidence. The clues gradually extend to a multi-year conspiracy within the palace, and Wan'er must find a way to break the deadlock while protecting her family.