Before we go any further, let us be clear that Fred Vargas is a woman. A Frenchwoman, to be precise, and a historian and archaeologist by profession -- or at least she was until she started writing novels, at which she has been very successful.
All in all, I gather that Vargas is the author of twelve titles in French. Three of them have so far been published in the UK, and Have Mercy On Us All has just been brought out by Simon and Schuster in the US; other books are to follow from the same source.
Have Mercy On Us All was a considerable hit in France: it was chosen by the booksellers of France and by the readers of Elle magazine as their Book of the Year. It's a crime novel: a mystery; a thriller, if you will. On the cover we are told that 'Commissaire Adamsberg investigates', and indeed that is her principal character and his job is to investigate murder.
The plot is amiably eccentric, and just about remains credible if examined in bright daylight; in the context of fiction, it works just fine. In the 14th arrondissement of Paris, a former merchant-navy captain has adopted the role of town crier. He will read out anything if you leave a note in his box, together with a modest fee, and one day someone starts asking him to read out obscure mediaeval texts. It emerges, in due course, that all these quotations relate to the plague. And before long people start dying of the plague. Or so it seems until Adamsberg gets going.
The great strength of the book is in its delineation of a dozen or so Parisians -- not always born and bred there, but assembled there. And a motley crew they are too. Always engaging, often amusing, and usually recognisable as bearing a resemblance to folk we have known.
If there is a weakness in the book, it is in the way that the author would have us believe that Adamsberg conducts himself. In real life, no senior police officer could possible investigate multiple murders in the same way as Adamsberg does. But never mind: this is a fictional entertainment, not a manual of police procedure.
Another weakness, if you're determined to find fault, is in the character who was allegedly a brilliant scientist in his twenties, but who now believes some wholly unscientific ideas about bubonic plague and how one can become immune to it. But again, most readers are just going to be grateful for a book which is entertaining, occasionally amusing and touching, and doesn't either insult our intelligence, cover us in gore, or try to explain the Meaning of Life.
This book is well planned, thoughtfully written, well observed, human, absorbing. It is not surprising to find that the author has won prizes and is published in 22 countries. The translation is by David Bellos, and has its own little eccentricities.