@Happy Squirrel, when I watched the series I was confused as well because the Catholic church is normally associated with Exoticisms and dealing with the Occult. However in the Anglican church the dept this Vicar is called to work for really exists! It's Deliverance Ministry. The author of the books seems quite obsessed with it and has researched it well but I never knew about it before. You can search google for loads of stories from Priests who were worked in that area!
The books are a series by the author Phil Rickman and are all labelled under the "Merrily Watkins series". Book 1 is called Wine of Angels and Book 2 which is this adapted tv series is called Midwinter of the Spirit. The 13th book of the series comes out this November and there is also a short story book about Merrily. I definitely want to read this series now and never heard of it before!
We got an extended preview of the series before it was shown here. I hope this youtube ad for it is global and not restricted to the UK but this is an overview of the series and it's tone and style. This is the first 3 mins of the first show -
https://www.youtube.com/watch?v=ayqFk391nwA
I really loved the series, something new and different on tv! best thing in ages! loved the characters! The woman doing the tarot reading was the nasty downstairs woman in Downton Abbey a few series ago, the one who was homophobic catching the Butler being gay. I am pretty certain it will be sold internationally and come out on DVD! I just feel sad they rushed the book in 3 episodes! The last episode was so rushed for a thrilling conclusion! I had to think for 2 days about why the series has it's title and it's related to the last episode. I think you could have got at least 6 episodes from this and a slower pace! But I will read it all when I read the actual book
If you want to watch this series and you are in the UK, it's on ITV Player for 15 more days after today for episode 1. I wouldn't recommend it to people who are sensitive to dark themes or horror though.