French writer Fred Vargas is a bit loopy for a crime writer, and I am grateful. I like hard-boiled, but it’s great to take a completely different direction sometimes.

vargasVargas’s key group of detectives – the slightly fey Commissaire Adamsberg, the all-knowing Danglard, the awe-inspiring Retancourt – always seem to attract the oddest of mysteries.

There is always something mythical, some ancient tale of horror, that is somehow involved in the murders they investigate.

In this case, there are two. There is Robespierre, the revolutionary who sent countless people to the guillotine, and there is the ancient Icelandic horror story of the afturganga, which both summons and mercilessly kills.

When the bodies start piling up around Paris, they are first linked to one piece of history, and then to the other.

There are talks of fog-bound isolation and death on a distant island, and also of the secret group who come together to re-create Robespierre’s dramatic days of revolution.

Adamsberg, as is his wont, follows his itches, and this time it almost causes a major rift.

If that makes no sense, apologies. It really does make perfect sense by the end. Vargas’s books always have thoroughly satisfying endings, but getting there can be quite a trip.

Vargas has now won four International Dagger awards, given to the best crime book in translation that year, something no one else has come close to.