Have Mercy On Us All By Fred Vargas trans. David Bellos

The plague returns to Paris

Reading a detective novel often feels like eating more for pleasure than nutrition. So it is a bonus when you discover a writer who packs their policiers with genuinely good things. Have Mercy On Us All is the first of a series of highly popular crime novels by the French (female) archaeologist and medievalist Fred Vargas to be translated into English. Although international in its observation of the conventions of the genre, it is very French in its atmosphere, full of gripping historical detail from the author's specialist field.

The novel is set in a nondescript area of modern Paris, an area in which, from moment to moment, you could be in one of a number of historical eras. To reinforce this sense of the past outweighing the present, Vargas has invented a key character who has resurrected the ancient metier of town crier. Joss LeGuern, formerly a Breton sailor, stands on a box in the square three times a day and reads out messages deposited by the public - unclassified ads meet street theatre.

Among the declarations of love and offers of runner beans for sale, a sinister note appears. Someone is copying out passages from accounts of the Black Death and depositing them in the box. Hand-painted signs also begin to appear on the doorways of apartments: a reverse figure four, a symbol commonly used in the 17th century to ward off the plague.

No sooner have a number of medievalists and other interested parties begun to realise that someone is warning of an imminent outbreak of plague in Paris than blackened corpses start to turn up. The murder inquiry is led by Adamsberg, a detective who goes on hunch and instinct. Adamsberg operates like a kind of historian. Though barely able to pull the top off his own beer, he has an extraordinary capacity to sense the outer reaches of a puzzle before being able to lay his hands on them, so that he almost always seems to know what he is looking for.

He may be professionally irksome, but he is devastatingly attractive to women, which will come as a relief to prospective casting directors. Adamsberg quickly realises that the plague, fear of which provokes something akin to the anthrax hysteria of 2001, is merely a cover for more focused crime directed at precise targets. Suspicion and fear become the murderer's greatest ally. When dogged by an unseen terror, we are all pre-modern at heart.

Apart from a good title (the original French was Pars Vite Reviens Tard), Have Mercy On Us All has not lost a great deal in David Bellos's expert translation, although it occasionally seems to have gained too much from Brewer's Dictionary of Phrase and Fable: a few too many cases of people knowing their onions or pulling the wool over each other's eyes. On the whole, this policier engages the mind without taking away its freedom, as some popular English crime novels seem to do. And not least among the pleasures of reading Vargas is the appetising thought that there are several more in the pipeline. Adamsberg may yet solve the crime and get his girl.

Helen Stevenson's 'Instructions for Visitors' is published by Black Swan