On the night of the massacre in the north, the Rong sisters witnessed the bloodshed all over their house. Their younger sister Rong Se was forced into a dry well by her mother, and her sister Rong Jin was abducted by the enemy general Tuoba Yuan. Ten years later, Rong Jin changed her name to Qing Hu and became a counselor in the North Kingdom, overthrowing the three cities with poisonous schemes. Rong Se lived in a gambling house and made a living by working as a prostitute. He unexpectedly met Shen Zhao, a young general from the South Kingdom, and became his secret agent; Jin was ordered to go south to negotiate peace, and Rong Se received an assassination order. The target was Qing Hu. The sisters' veil slipped at the Rainy Night Inn and the tip of the knife stopped in front of their throats. Rong Se was arrested and imprisoned. Rong Jin pretended not to know but sneaked into the cell to deliver medicine late at night. However, he heard the mysterious man in prison saying "Jin Se's Happy Years" to Rong Se; the sisters teamed up to escape from prison, but found that they were chasing him. The killer was actually the core figure of each camp, and the same hand behind the scenes controlled the war between the two countries; Rong Jin was forced to use poison on Tuoba Yuan, and Rong Se killed Shen Zhao's substitute with his own hands. The secret organization "Jin Se Huanian" surfaced. Its members used the code name of Qin, chess, calligraphy and painting to select girls from troubled families and train them as chess pieces; the sisters split up and sneaked into the hinterland of the organization. One of them pretended to be a chess piece, and the other pretended to surrender, but when they saw their mother's relics in the secret room on the seventh floor, they learned that their maternal lineage was the founding bloodline of the organization; the sisters must choose one person to inherit control of the organization, and the other must be sacrificed. In the end, they faked their own death to kill the top leaders of the organization, but at the last moment due to information differences, they ended up fighting each other.
