The Inquirers: they were a band of private detectives who lived beneath the streets of London in a labyrinth of twisted tunnels and ancient hallways, the entrance to which no one had every found.

Set in London 1958, this book takes us below the streets of familiar London to the mysterious underground world of the Inquirers. Marion Lane can’t believe her luck when she is offered a job in Miss Brickett’s Secondhand Books and Curiosities, little realising that she has, in fact, been offered an apprenticeship as an Inquirer. She loves this underground world, where she can escape her grandmother Dolores’ constant matchmaking. Marion is a complex character, dealing with the grief of losing her mother, and finding her feet in this new environment. She is determined to pass all her exams to become an Inquirer.

However, when a filing assistant is found brutally murdered, Marion’s mentor Frank is arrested on suspicion of her murder. Marion, together with her friends, must explore forbidden tunnels to uncover the true murderer.

Willberg has created a fascination underground world, full of menace, danger and fantastic gadgets. It’s hard not to draw comparisons with Harry Potter’s world, particularly when a map that reflects people’s movements is an integral part of the plot. But I think it’s an unfair comparison; Miss Brickett’s has enough unique features to stand on its own two feet.

I would have liked to have see more of the other mysteries that the agency investigates, but hopefully the next book will expand into that territory. Although this book looks like a cosy crime, it’s not; there are a number of rather nasty deaths (just to give you a heads-up).