Modern top assassin Netherworld Wen Nianshu transmigrates overnight into the bullied, foolish legitimate daughter of the Prime Minister's estate, forced into a proxy marriage with Prince Regent Ye Wuchen, whose first five wives all died on their wedding night. Feigning foolishness on the surface while plotting step by step in secret, she ruins Wen Ruyue's appearance, punishes Liu Rou, and disciplines her scumbag father, only to be controlled by the Empress Dowager's poison upon entering the palace. The cold-faced Prince Regent Ye Wuchen goes from probing to protecting, publicly bestowing singular favor and acknowledging only her. With revenge and true love intertwined, she fights her way through the capital and becomes the sole light in his darkness.