A Rule Against Murder: A Chief Inspector Gamache Novel (2008)

From Louise Penny's web site:

THE MURDER STONE is the fourth Chief Inspector Gamache mystery, and the last in the seasonal cycle that began with STILL LIFE.

THE MURDER STONE is set over the course of one summer week at the Manoir Bellechasse, a remote luxury inn on the shores of Lac Massawippi, in Quebec. It's to this inn that Armand Gamache has brought Reine Marie to celebrate a wedding anniversary. But while they're surrounded by nature, it soon becomes clear there's something deeply unnatural there with them. Perhaps it's the Finney family. Cultured, gracious, the more they smile the more vicious they become. Perhaps its one of the young workers at the remote Manoir, suffering cabin fever so far from civilization.

Guests go to the elegant old inn to escape the past. But it comes looking for them. And as the stifling heat closes in, as the humidity rises, as a terrible summer storm approaches and crashes into the old log lodge, it finds them. A body is discovered. It's up to Chief Inspector Gamache and his team to figure out how the victim could have been murdered, and who among them did it.

The chase takes him to the village of Three Pines, into the dark corners of his own past, and finally to a harrowing climax.

'The mind is its own place,' Gamache quotes. 'And in itself Can make a Heav'n of Hell, a Hell of Heav'n.'

At the lovely Manoir Bellechasse he finds both.

I did want to mention that this book will be published January in the United States, but under a different title. They were inspired by an exchange between two of the characters, and have chosen the title, A RULE AGAINST MURDER.