Four seasons in and this thing still refuses to explain itself, which is exactly the deal you signed up for. The format hasn't changed and doesn't need to: a girl who won't say what she is, a young monk who keeps asking anyway, and a demon doctor who treats the supernatural like a diagnosis instead of a sin. Every case walks in as a human problem and walks out as something older, and the cure usually costs the patient more than the illness did. If you stuck around this long, it's because the show keeps quietly proving that the demons are rarely the worst thing in the room. Twelve more house calls, twelve more people who asked for help and got the truth instead.

Tao Yao keeps traveling in this fourth season, joined by the young monk Moya, the small fox demon Gungun and Liu Gongzi, an old neighbor from Taodu. They are still hunting for the lost Hundred Demon Spectrum. On the road they meet six monsters, among them Baizhi, Fengguo, Yuhu, Fengsheng and Pengyu, and they work to cure the stubborn illnesses that afflict such creatures.