The Stranger Diaries by Elly Griffiths

Elly Griffiths is best known for her detective novels, the Ruth Galloway series and the Stephens and Mephisto series, and I'm a big fan of both (reviews here). The Stranger Diaries, however, is a standalone mystery that, although it does feature a police investigation, reads to me more like a psychological thriller.

Claire Cassidy is writing a book about RM Holland, a fictional writer of ghost stories (think MR James) best known for a short story called The Stranger. She's also an English teacher at a secondary school which is partly located in what used to be Holland's house - as someone who also went to an ordinary comprehensive school that was mostly ugly and modern but a small portion of which was an old mansion house, I identified with this location quite strongly. One day her friend and colleague Ella is murdered, and at around the same time, strange notes start to appear in Claire's diary. Who is writing them, how are they getting into the house, and how are they connected to Ella's shocking death?

As well as Claire's point of view, there are also portions of the story narrated by Georgie, her teenage daughter, who has secret creative writing ambitions of her own, and by DS Harbinder Kaur, the police officer assigned to the murder case. The multiple points of view work well here. One of my common complaints about the psychological thriller genre of late is how smugly affluent and middle-class the protagonists seem to be, and Claire is very much a character in that mould, but the key thing here is that this is acknowledged, often acerbically, by the no-nonsense Harbinder.

The plot escalates gradually in this book, which is strong on atmosphere and sense of place, although when the mystery is actually solved at the end, it feels a little rushed  and a little more explanation and exploration of motive might have helped - in some ways, the conclusion felt as if it came from a different sort of book. There's also an additional element, touched on by Harbinder when she recalls a terrifying incident she witnessed as a pupil at the school where Claire works, that I'd like to have seen developed - as it is, it feels like a slightly out-of-place add-on. However, this novel is creepy and cleverly-plotted with believable, well-observed characters and the story felt fresh and original. It certainly did keep me turning the pages - and, as it's set in the approach to Christmas, it's a particularly good read for a dark December night.