Synopsis：Cheng Yuanfang, the heiress of a well-known domestic enterprise, suddenly arrives and commissions Ayang and Kevin, private investigators from a credit agency, to help find her missing sister-in-law, Ding Xiaohan. They soon discover that Ding Xiaohan may have been killed by Yuanfang's mentally unstable brother, but her whereabouts remain unknown. Meanwhile, Ayang gradually becomes attracted to Yuanfang and resolves to protect her from any harm at all costs. Who is the real murderer? Who is lurking in the dark night, waiting for an opportunity to take revenge?