Kim Taehyung, known in the underworld as the most dangerous mafia king, rules with unmatched power, intelligence, and fear. Cold, ruthless, and strategic in business and war, he shows no mercy to his enemies. But behind his brutal reputation, he has a soft, loving side reserved only for his wife. Two years ago, after being injured on a mission, he was saved by a mysterious girl he believed was ordinary. Since then, he fell deeply in love with her and eventually married her—completely unaware that she is actually the feared mafia queen “Shadow,” the very person he has been unknowingly searching for.