Fantastical suspense crime solving about worlds linked through "Gates" - Main character is an author set in London, other character is Police detective and Magpie

[Suziethorp]

Set in currentish time period - I only read it within the last couple of years. I dont think it was from a series but it may have been. where one of the main characters was a woman writer who was trying to find out what happened at her grandfathers house - there was a fire but was it deliberately lit in an attempt to burn a special tablet that could cause all the gates to the other world to open and chaos would happen. She goes to visit her father who lives in new zealand or maybe australia. One of the central characters is a police detective. One of the central characters from the other world is a shapeshifter who takes on the body of a magpie in our world. In the ther world all sorts of trials and tribulations happen. She looks after the 'jesus-like' character - there had been a split in loyalties at some point and a big war.

[Becca]

The Absolute Book by Elizabeth Knox?