Recently I’ve been coming to police procedurals series that are already several instalments in. Yes, I’m looking at you Lin Anderson and Rhona MacLeod, and Ann Cleeves and Matthew Venn. So it’s a delight to start the DCI Christine Caplan series right at the beginning. Like almost everything else I’ve read this summer, The Devil Stone, by Caro Ramsay, involves a coastal location and the lead cop a bit out of water. But The Devil Stone takes everything to the max. It isn’t what you think it is going to be about, and at times I am not sure I’m following everything. It’s really surprising and utterly satisfying. A lazy parallel is Line of Duty but there are times I’m minded of one of the more controversial scenes in Game of Thrones.

Let’s start with what this isn’t. The blurb on the back says that there is a mass murder ‘in a Satanic mass’. It’s true that there’s a mention of Aleister Crowley here and there, and a hint that darker forces are at large. But it turns out that things are plenty dark without any of this other stuff.

Christine Caplan is not having a great time. She is busted down to DI for professional misconduct and at various times during this novel there are attacks on her reputation, her family and, eventually, on Caplan herself. Her home life is difficult but while the difficult teenage son provides the kind of stresses that we’ve come across before, there are problems in her marriage which mix up the emotions of guilt, frustration and a no-nonsense matter-of-factness that come to characterise this new series lead. Caplan is up against a faceless adversary or adversaries, at multiple levels within Police Scotland. She has few obvious allies. She’s resourceful and quick, but as you would expect there are moments of self-doubt or a loss of confidence. In order to survive, she must trust someone she knows on some levels to be untrustworthy.

This tension outweighs the actual mystery which in a sense is a shame because it’s a good one, tying together perennial issues of generational privilege and also generational poverty, substance addiction, power, tradition and corruption. The final showdown is a set piece which is audacious in its construction.

Potential bent coppers are the obvious link to AC-12 but there are times when Ramsay takes us somewhere else. When you can’t trust anyone, when there are looks and glances heavy with meaning but it isn’t clear what that meaning is, when you, despite holding the book in your hands, are not totally sure what’s going on, there’s a level of ambiguity and uncertainty that when done well – as this is – causes we readers to have to stop, think, try to work out what we’d do, what we’ve just read means. I have to read the showdown a couple of times. Is it obvious what Caplan should do? No. This is complex, demanding entertainment. It’s a bit like The Long Night, the Game of Thrones episode in which the White Walkers take on the army of the living up at Winterfell. You may recall that many people complained about the production lighting because they couldn’t see what was going on. But that was precisely the point, and I love that Ramsay keeps us guessing.

This is a fabulous new series, and The Devil Stone is your chance to get in at the beginning. Take it. With any luck this one will run and run.

Thanks to Canongate for the review copy and to Anne Cater for the blog tour invitation.