For those of you not familiar with Aaronovitch’s ‘Rivers of London’ series, they are fantasy crime mysteries featuring apprentice wizard, Peter Grant, of the London Metropolitan Police’s Special Assessment Unit (otherwise known as The Folly) under the mentorship of DCI Thomas Nightingale. Peter has several cousins and in this book, young Abigail gets her own crime to solve, before she becomes more actively involved in later episodes.

Set in the summer of 2013, Abi lives near Hampstead Heath (the endpapers have a map), it is the summer vacation and she is left to her own devices. When several local teenagers go missing, only to reappear with no memory of what had happened, Abi sets out to investigate. With the help of a group of talking foxes, she finds where the teens have gone. As she has some magical talent that is as yet untrained, she can tell that the house has supernatural properties and has trapped them.

Abigail’s voice is very distinctive and she speaks in her local vernacular. Fortunately, there are footnotes, written by Harold Postmartin, archivist of The Folly, explaining slang terms and cultural references. Parts of the book do become confusing but they are to Abigail, too, so making sense of them is a revelation to both character and reader.

It is not necessary to have read all the ‘Rivers of London’ books but it helps to be familiar with the background.

Reviewed by Lynne Babbage