In some ways, the greatest mystery of these Peter Grant books is why they are so enjoyable. I’m pretty sure the author has only slightly more idea about what is going on than I have – the plot holes are often so glaring you need to wear sunglasses to keep reading – the writing is so right on that there is some legitimate doubt as to whether the PC in PC Peter Grant actually stands for ‘police constable’, and I strongly suspect that Aaronovitch is slowly realising just how difficult it is to wield magic in a story universe that is ostensibly our own without it devolving into something little more than engineering with pretty Latin terminology… and yet, and yet, these stories are just so much fun!