Qi Shi merely agreed to mourn at someone's grave, never expecting that Shen Yuan, the man buried there, would actually follow him home that very night. He cannot remember how he died, nor does he know why he is trapped by Qi Shi's side. From then on, Qi Shi begins to see another world: children who disappeared years ago, brides who have died, unclaimed corpses, and secrets deliberately buried by the living. With Zhou Lele joining them, the three follow the lingering obsessions left behind by the dead, gradually uncovering the truth. But as their investigations deepen, they begin to realize that those seemingly unrelated deaths may have been connected by the very same thread all along!