“Once?”

His mentor had immediately picked up on the significance of that. A single, catastrophic blow. It was extremely rare. A person, if hit once, was almost certainly hit often, the murderer in a rage. He’d rain blow after blow on his victim. Almost never did they find just one blow, hard enough to kill. It meant someone was filled with enough rage to power a terrible blow, but enough control to stop there. It was a frightening combination.

“The victim had no identification, but we finally found a cabin hidden in the woods, where he lived and where he’d been murdered. Émile, you should have seen what was in there.”

Émile Comeau had a vivid imagination, fed by decades of grisly discoveries. He waited for Gamache to describe the terrible cabin.

“It was filled with treasure.”

“Treasure?”

“I know,” smiled Gamache, seeing Émile’s face. “We weren’t expecting it either. It was unbelievable. Antiques and artifacts. Priceless.”

He had his mentor’s full attention. Émile sat forward, his lean hands holding each other, relaxed and alert. Once a hunter of killers, always that, and he could smell blood. Everything Gamache knew about homicide he’d learned from this man. And more besides.

“Go on,” said Comeau.

“There were signed first editions, ancient pottery, leaded glass thousands of years old. There was a panel from the Amber Room and dinnerware once belonging to Catherine the Great.”

And a violin. In a breath Gamache was back in that cabin watching Agent Paul Morin. Gangly, awkward, young, picking up the priceless violin, tucking it under his chin and leaning into it. His body suddenly making sense, as though bred to play this instrument. And filling the rustic, log cabin with the most beautiful, haunting Celtic lament.

“Armand?”

“Sorry,” Gamache came back to the stone home in Quebec City. “I was just remembering something.”

His mentor examined him. “All right?”

Gamache gave a nod and smiled. “A tune.”

“You found out who killed this recluse though?”

“We did. The evidence was overwhelming. We found the murder weapon and other things from the cabin in the bistro.”

“Olivier was the murderer?” Émile lifted the letters and Gamache nodded.

“It was hard for everyone to believe, hard for me to believe, but it was the truth.”

Émile watched his companion. He knew Armand well. “You liked him, this Olivier?”

“He was a friend. Is a friend.”

Gamache remembered again sitting in the cheery bistro, holding the evidence that damned his friend. The terrible realization that Olivier was indeed the murderer. He’d taken the man’s treasure from his cabin. But more than that. He’d taken the man’s life.

“You said the body was found in the bistro, but he was murdered in his own cabin? Is that what Gabri means? Why would Olivier move the body from the cabin to the bistro?”

Gamache didn’t say anything for a long time, and Émile gave him that time, sipping his wine, thinking his own thoughts, staring into the soft flames and waiting.

Finally Gamache looked at Émile. “Gabri asks a good question.”

“Are they partners?”

Gamache nodded.

“Well, he just doesn’t want to believe Olivier did it. That’s all.”

“That’s true, he doesn’t. But the question is still good. If Olivier murdered the Hermit in a remote cabin, why move the body to a place it would be found?”

“And his own place at that.”

“Well, no, that’s where it gets complicated. He actually moved it to a nearby inn and spa. He admits to moving the body, to try to ruin the spa. He saw it as a threat.”

“So you have your answer.”

“But that’s just it,” said Gamache, turning so that his whole body faced Émile. “Olivier says he found the Hermit already dead and decided to use the body as a kind of weapon, to hurt the competition. But he says if he’d actually murdered the man he’d never have moved the body. He’d have left it there, or taken it into the woods to be eaten by coyotes. Why would a murderer kill someone then make sure the body was found?”

“But wait a second,” said Émile, trying to piece it together. “You said the body was found in Olivier’s own bistro. How did that happen?”

“A bit awkward for Olivier that,” said Gamache. “The owner of the inn and spa had the same idea. When he found the body, he moved it to the bistro, to try to ruin Olivier.”