The October Man, by Ben Aaronovitch

The outrageously named Tobias Winter and Vanessa Sommer are two cops teamed up to investigate a peculiar death - the victim consumed by the noble rot used in making some kinds of wine. Winter, who narrates this case, is the German equivalent of Peter Grant, the narrator of the other Rivers of London books - smart-talking, shrewd and a junior wizard.

Having only read Lies Sleeping last month, I'd hoped this new instalment would pick up where that ended but this is more of a side-step - apparently, Peter isn't even aware of Winter's existence. I can see that the German police would want to recruit someone very like Peter, but if there's a criticism it's that they're not more distinct in attitude and patter. If I were editing this, I might suggest Vanessa - the non-magical sceptic - should narrate it.

But for that small concern, how brilliant to explore another part of the same world. How thrilling to get some more tantalising detail about what might have happened in the Second World War that Peter's boss, Nightingale, will only allude to - and from a German perspective. It's surely prood of the strength and richness of the world Ben has created that such a side-step is conceivable, let alone done so well.

This is a typically fast-moving, slick murder mystery, full of wry observation and stuff that feels totally real, grounding the magic so we take it in our stride. It's 20 years since I took my higher certificate in wines and spirits (yes, really) but the viticulture all seems right. Ben knows London intimately, so it's quite an achievement to suggest the same confident command of Trier. The novella ends with the case resolved, but suggesting there's more to come. I hope so.