This is an ongoing continuation of the previous book which is book 3 in the series. Not sure why the author felt this was necessary. Anyway, you could actually pick up the storyline without reading book 3, so it doesn’t really matter.
A serial killer is now in Cornwall, kidnapping, mutilating and killing young woman. This is brought sharply into focus for DI Austin when a policewoman is kidnapped and there is a race against time to save her.
This is probably the best book in the series so far. If only we could see that proof reader on the horizon.