Reborn on the wedding night, Shen Qinghuan holds the dual systems of poisonous concubine and merit, and counterattacks to kill the poisonous concubine sent by her eldest sister, starting from the death of the substitute princess. The sister-in-law and the prince wanted to get rid of her with the help of the violent prince, but they didn't know that she was no longer the cowardly concubine in her previous life. She used poison to kill people and medical skills to save people. In the murderous plot, they discovered that she was actually the orphan of the Chu family who was executed by the whole family seventeen years ago! The tyrant prince Xiao Jue only found this "stand-in" interesting at first, and watched her fight, break up conspiracies, and take over old subordinates with cold eyes, but he fell into his heart as she fought back again and again. When the eldest sister and the mastermind behind the scenes launched a general attack, Chu Qinghuan used herself as bait and showed her final trump card: the most powerful poison in the world was the one you forced me to plant; and the strongest shield in the world is the man beside me who is willing to overturn the world for me. From being a substitute in the palace to standing by her side in the world, she crawled back from hell and demanded blood repayment from all her enemies. She also wanted to share the world with the man who saw through her from the beginning but allowed her to become evil.