‘That’s CC’s corporate logo. It’s on the cover of her book, kind of. It’s all smudged, a not very good reproduction, but that’s what it is.’

‘You were right,’ said Beauvoir. ‘CC stopped the video at minute seventeen to get a good look at the front of the boat. She must have recognized it as Eleanor’s emblem, and wanted to copy it.’

‘Everything makes sense,’ murmured Lemieux.

‘How’d you make the connection?’ Beauvoir asked.

‘I had an unfair advantage,’ admitted Gamache. ‘Lyon showed me CC’s book and pointed out the logo. It’s unforgettable.’ So this explained the ridiculous choice of a belligerent eagle as a logo, he thought. It was Eleanor’s emblem.

‘There’s something I need to show you.’ Gamache walked over to his satchel and removed the photographs taken by Saul Petrov. The team pulled their chairs up to the conference table while Gamache spread them out.

‘I figured out why CC grabbed the chair in front of her,’ he said, nodding to the series of pictures. ‘It’s all there.’

They stared and after a minute Gamache took pity on them. They were all tired and hungry and Agent Lacoste had a long drive back to Montreal.

‘See here?’ He pointed to one of the early shots of CC watching the curling. ‘The chair looks fine, right?’

They nodded.

‘Now look here.’ He pointed to one of the last pictures of CC.

‘My God, it’s so obvious. How could I have missed it?’ Beauvoir looked from the pictures to Gamache in astonishment. ‘It’s crooked.’

‘So?’ said Lacoste.

‘Over and over again the people who knew her, or even met her casually, said the same thing. CC obsessively rearranged everything around her. A chair like this,’ Gamache pointed to the tilted chair, one corner sunk into the snow, ‘was guaranteed to get a reaction. The only surprise is that it took her so long.’

‘Except, as you pointed out,’ said Nichol, ‘the chair was just fine to begin with. Someone must have shoved it off kilter.’

Gamache nodded. Was that what was on the roll of film Petrov burned? Did it show a villager casually wandering by and leaning on the chair? Did the villager then go to the generator and wait for CC to get up? And when she did all he had to do was attach the booster cables, and bang. Murder.

It was brilliant and almost elegant.

But who did it? Richard Lyon was the perfect suspect. He knew his wife would reach for the chair that had gone askew.

‘That photographer was hiding something,’ said Beauvoir.

‘I agree,’ said Gamache. ‘He burned a roll of film in his fireplace just before we arrived. I think it was of the murder.’

‘Why would he destroy it, though?’ asked Lemieux. ‘As he said, if he had a picture of the murderer it would prove his own innocence.’