Seeking Whom He May Devour by Fred Vargas, trans David Bellos

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Fred Vargas's ingenious French thrillers are haunted by ancient horrors. In Have Mercy On Us All, the first to be published in English, a sort of amateur town crier sets up in a Parisian square to read the messages the locals put in his box. Soon, amid requests for recipes and complaints about noisy neighbours, come strange fragmentary texts predicting the return of the Black Death. When a blackened body turns up, media coverage leads to mass hysteria.

A similar wave of panic strikes a remote Alpine village in Seeking Whom He May Devour, when first sheep and then a foul-mouthed farmer are found savagely mutilated. Could this be the work of a ferocious lone wolf - or even a werewolf?

Legend has it that werewolves have no body hair so, when a beardless recluse called Massart seems to have disappeared, rumours soon make him the prime suspect. Could the map found in his hut plot the route he has planned for a killing spree?

The farmer had a devoted old shepherd and an adoptive black son who are keen to set out in pursuit and avenge her death. Since neither can drive, they rope in Camille, a composer-cum-plumber who is living in the village with her Canadian boyfriend. This improbable trio embarks on a crazy "road movie" in a stinking cattle-wagon but, as the corpses mount up, quickly realise they have bitten off more than they can chew.

They know they should go to the police, but where can they find "a special sort of policeman... who'd pass on all the info without giving us any grief, and who'd let us carry on tracking the vampire down"? It is only then that Camille remembers her ex-lover, Commissaire Jean-Baptiste Adamsberg.

Vargas is a historian and archaeologist as well as a bestselling crime novelist. Her professional knowledge of the Black Death and peasant superstition gives the books far more depth than the pseudo-scholarship and cod philosophising found in most "intellectual thrillers".

She claims to be an ultra-rationalist, although she is clearly fascinated by outbreaks of irrational fear. And in Adamsberg she has created the ultimate intuitive detective, a man who is "quite fond of intangibles", relies on aimless reverie as much as accumulation of evidence, and has learnt to treat his brain "like an ocean that you trust entirely to feed you well, but which you've long ago given up trying to tame".

Many cops would react badly to an old flame who turned up out of the blue and asked for help in finding a werewolf. But Adamsberg is no ordinary cop and has already become interested in the case because of a Pyrenean childhood "shrouded in old folks' accounts of the saga of the last wild wolves in France". Only he can find his way through "the darkness enveloping the whole story", while negotiating the sexual triangle between himself, Camille and her hunky Canadian. Slick, creepy and full of engagingly odd characters, this thriller is a class act.

Matthew J Reisz edits the 'Jewish Quarterly'