My favorite supernatural cop, Detective Constable Peter Grant, is back, in this ninth novel in Ben Aaronivitch’s “Rivers of London” series. He’s still working for the London Metropolitan Police Special Assessment Unit (the one that takes care of the “weird bollocks” without using the “M” word unless absolutely necessary) and learning magic from DCI Thomas Nightingale. And he is every bit as good at following police procedure, criticizing London’s architecture, and messing up magic spells as he has always been.
This time there’s something that looks like an avenging angel loose in London, possibly called up by an ancient lamp and definitely associated with seven mysterious enchanted rings. Someone is stealing those rings, and their owners are ending up messily dead. Given the title, Amongst Our Weapons, and section headings (“Surprise . . .,” “Fear . . .,” “Ruthless Efficiency . . .,” and etc.), you should totally expect the Spanish Inquisition, though the plot will work just fine even if you don’t.