Across the Lethe River sits the Boundary Realm, a place of endless night where ghost messengers keep the world's deaths in balance. The Black and White Warriors are messengers who gather spirits from the Human Realm. Xiaohei and Xiaobai are a pair of these warriors on the lowest rung, and since an incident inside the One Hundred Ghost Great Seal, their bond has turned delicate. Meanwhile, the truth about who Xiaobai really is starts to come out. This second season mixes action, comedy and fantasy.