Everyone feared Lu Beichen. Cold. Powerful. Untouchable. As the CEO of Lu Group, he was a man nobody dared to approach—especially when he was angry. Then Su Tangtang walked into his life. She was just a nineteen-year-old girl trying to earn enough money to support her parents. She didn't care about status, wealth, or powerful men. She didn't even know who Lu Beichen was. But somehow, the girl who wasn't afraid of him became the only person who could calm the darkness inside him. As their strange connection grows, Tangtang begins to uncover secrets Beichen has spent his entire life hiding. Why does her presence affect him? What is the darkness inside him? And when the truth about the Lu family finally comes to light, will their unexpected bond survive it? She never planned to enter the Devil's world. But somehow, she became the girl who made the Devil smile.