Su Nian was frail since childhood and was abandoned in an ancient temple. He was raised by his adoptive parents. When she was twenty-one years old, she suddenly became dizzy in the university library and heard foxes croaking every night after that. An injured white fox broke into her bedroom in the middle of the night and made a contract with her - to use her body to recuperate and accumulate merit for her.
From then on, she could see dead souls and hear injustice. She cooperated with the detective Jiang Ye to rescue the souls of the dead, solve unsolved cases, suppress evil spirits, and gradually uncovered the mystery of her life experience: It turned out that she came with the mission of guarding the world and subduing demons, and this white fox was the Taoist companion in her previous life who had been waiting for her for three hundred years.
