Lin Wanyue transmigrates into an ancient romance novel as a fake heiress who is destined to die within a year. At the very beginning, the original owner has just jumped into a lake for a new third-place scholar, becoming the subject of gossip throughout the city. To protect herself, Lin Wanyue chooses to admit her mistakes and keep a low profile, hoping to get through the crisis safely. Unexpectedly, she becomes entangled in an old case, bringing her into contact with her nominal fiancé, Prince of Linzi, Zhao Jiuxi. Meanwhile, the real heiress finally returns to claim her rightful place in the family. Rather than driving Lin Wanyue away, the real heiress actually urges her to marry the prince first. Caught in a complicated game of intrigue, Lin Wanyue investigates cases to stay alive while navigating the competing forces around her, gradually uncovering a long-hidden secret from the previous dynasty.