Detective Constable Peter Grant must navigate the treacherous waters of London's magical underworld to protect a Russian witch and confront a dangerous nemesis. As the second wizard policeman in London, Peter Grant is still learning the ropes under his boss, Inspector Thomas Nightingale. Their primary concern is the Faceless Man and his former partner, Lesley May, who has turned to crime after a disfiguring injury. Meanwhile, they must ensure the safety of Varvara, a Russian witch who has aided the police and now has a substantial bounty on her head.

This novella is likely to appeal to fans of the Rivers of London series, offering a focused narrative that expands on the established world and characters. The premise suggests a blend of magical investigation and personal conflict, typical of the series' urban fantasy elements. Readers can expect a continuation of Peter Grant's growth as a wizard policeman, facing threats that require both magical and deductive skills. The inclusion of familiar antagonists like the Faceless Man and Lesley May provides continuity and raises the stakes for the protagonists.