Sixteen years after a botched arrest leaves a serial killer at large, a guilt-ridden cop and a determined intern reunite to uncover dark secrets and catch the real murderer.

Fan Dayao, the mighty Tiger Demon King, rules Qianchun Mountain with absolute power. Shen Wangchen, a frail and distant nobleman’s son, seeks a cat demon to cure his illness. When they meet, an unlikely and humorous cohabitation between human and demon begins.