What’s behind the doors of your advent calendar? A chocolate? A tea bag? A vintage crime book because you were smart enough to buy one from Coffee and Crime? Well, whatever you have, the last thing you want is a negative of a photograph of a crime scene. Unless you’re weird, obviously…

Anyway, that’s exactly what arrives at DS Eddie Carmine’s police station. Twenty doors show twenty different crime scenes, one from each of the past twenty years – but it’s the blank ones that worry DS Carmine and DC Becky Greene. It soon becomes clear that the killer is accelerating their plan – but will they manage to complete the calendar?

I saw a few recommendations for this one when looking for Christmas mysteries. Written before the current avalanche of Christmas titles, I figured it was worth a look.

It’s a book that is really hard to review, as I really enjoyed reading it – it’s a real page turner as we follow Becky, Eddie, the initially-mysterious Carly and “The Photographer” as the story unfolds. The insights into the killer are pretty well done – this isn’t the sort of serial killer where he spends pages talking about what his victims’ insides remind him of, or what he is going to do with them – he talks about his motives for doing what he is doing instead, drip-feeding ideas behind his motivation. The tension ratchets up nicely as the picture becomes clearer and Carly’s relevance to the story is really well-paced.

There are a couple of plot beats that seemed conveniently timed – Carmine suddenly remembering a conversation with the killer when he was investigating one of the windows in years past seemed to come out of nowhere – and there’s an odd couple of chapters where the killer is fuming about the fact that nobody seems to be reacting to his advent calendar, only to know everything about Becky as an investigating officer pages later. And personally I could have done with more of a surprise as to the identity of the killer – this is more a thriller really – but the final reveal is less Chekhov’s gun than Chekhov’s grain of salt. Also, I never understood why the killer took twenty years to accelerate things…

I think as long as you go into this for the ride and don’t go looking for a traditional mystery, you’ll enjoy this a lot – some of my niggles here come in hindsight, rather than when they occurred. Who knows, maybe next Christmas, maybe I’ll take a look at the follow-up?