It seemed like a good bit of fun at the time…

We open up in favoured Simenon territory, the bedroom, where we find Tony and Andrée getting their breath back after some eye-popping sex. None of the many women 33-year-old Tony had known “had given him as much pleasure as she had, an animal pleasure, complete and wholehearted, untainted afterwards by any disgust, lassitude or regret”.

This is the “blue room” in the Hôtel des Voyageurs on the Place de La Gare in Triant, a small town in the French countryside. Tony’s brother Vincent owns the place, and knows what’s going on. Tony and Andrée are both married, though not to each other.

The “blue” refers to the décor and not the adulterers’ frenzied coital activities while there, though the sexually charged Simenon (he of the “10,000 women”, 8000 of them prostitutes) goes a bit nearer the knuckle than normal with a racy description or two. Still, this was published in France in 1964 (as “La chamber bleue”) as the birth control pill heralded a sexual revolution, and don’t the French have a bit of a liberal reputation in this regard?

Simenon slips in the background. Tony Falcone, of Italian descent, has a company selling agricultural machinery in the village of Saint-Justin-du-Loup, near Triant. He lives in the village with his modest wife of seven years, Gisele, and their daughter Marianne, and so do Andrée and her sickly and morose husband Nicolas Despierre, owner of a grocery store.

The two adulterers went to school together but there was never anything between them until Andrée seduced Tony when he stopped in his car one evening to fix her broken-down Citroen at the side of the road. In a typical Simenon fantasy, Tony discovers that Andrée always had a soft spot for him and she drags him off for a fuck (that’s how the brazen lady puts it) in the tall grass and nettles beside Bois de Sarelle.

Subsequently they have met eight times in the blue room over the past 11 months, and, as stated, the book begins after their latest sweaty session on a ravaged bed. Suddenly, immediately, the scene shifts in the blink of a sentence to mention of Tony being questioned by his lawyer, Maître Demarié. When and why we don’t know yet.

Then it’s back to the naked bodies, sated and recovering from their carnal delights, with another quick switch from Simenon in which it is revealed that Tony met first a sergeant, then a lieutenant from the Police Judiciaire in Poitiers followed by a psychiatrist, Professor Bigot, and the examining magistrate, Diem.

What’s going on? Why the interrogations? What does Simenon have up his sleeve? Masterfully, he leads us on. It is a page-turner. Tony is in handcuffs for the questioning – it’s something serious. With Simenon, a murder is virtually guaranteed but if there was one we must wait to find out who and how. Anyway, you can bet Tony hasn’t been busted for stealing any hotel towels.

Thanks to Simenon’s fine balancing trick, with a peep here and a peep there, we aren’t going to find out the nature of the crime until the big revelation near the end. It’s a sort of literary carrot-and-donkey trick. Perhaps it’s not a previously unknown novelistic technique but Simenon has it down pat. The jumps in time backwards and forwards are brilliantly handled; no seams visible.

Along the way, as the crime is investigated, every corner of Tony’s life is examined. Things turn nasty. Turns out there are two dead bodies. And when the end comes, it’s a wham-bam. Plus, we now realise, it all basically related back to one casual question that Andrée had asked Tony in the opening pages in the blue room, and Tony obviously never realised what would be the consequences of his unconsidered answer. It’s the clue we missed.

One more neat trick, then, by Simenon, pulling off a classy whodunnit where you don’t actually know who dunn it or what was dunn until near the denouement. Moral (spoiler alert): sometimes it’s better to keep your pecker in your pants.