The series is based on Phil Rickman's "Merrily Watkins" series of books, of which "Midwinter of the Spirit" is the second in the series. [1] This series follows country vicar Merrily Watkins, who is one of the few women priests working as an exorcist in the UK. When a grisly murder takes place in her local area, the police come calling for her assistance.[2]