‘At the height of the fire, when we were trying to save you…’ He sat down, forcing her to look at him. She was pale and radiated smoke as though it had seeped beneath her skin. Her clothes were ill fitting and slightly dirty, a grease stain on her lapel, dark smudges round her cuffs. Her hair was badly cut and falling into her eyes. He felt like giving her his credit card with instructions to buy nice clothes. He felt like passing his large, tired hand in front of her brow to sweep the dull hair from her angry eyes. He did neither, of course. ‘Something was said. I suspect you heard it. One of us yelled, “She’s not worth it.”’

Now she looked at him straight on, her face full of bitterness.

Gamache stared back. ‘I’m sorry,’ he said. ‘It’s time for the truth, for both of us.’

He told her what he had in mind, his plan. And she listened. When he’d finished he asked her to keep it to herself. She agreed and thought two things. That he was probably smarter than she’d given him credit for, and that he was going down. After he was gone she brought out her cell phone and made a quick, discreet call.

‘I decided to tell him about Uncle Saul,’ she whispered. ‘I know, I know. It wasn’t part of the plan. Yes sir. But I’m on the ground here and it was a decision I had to make at the last moment,’ she lied. She couldn’t possibly admit it had slipped out in a vulnerable moment. He’d think her weak. ‘Yes, it was a risk, I agree. I was afraid he’d take it the wrong way, but I think it worked. It seemed to appeal to him.’ At least that part was true. Then she told him everything Gamache had said to her.

By the end of the day more than eight inches of puffy snow had fallen. Not the kind that made good snowmen, but it made for great snow angels and Gamache could see kids flinging themselves into the fluffy whiteness, flapping their arms and legs.

The fire inspector had just left.

It would take a while, of course, but his initial finding was that the fire was caused by creosote.

‘So someone set fire to creosote and killed Petrov,’ said Beauvoir.

‘Exactly,’ confirmed the fire inspector. ‘Petrov set fire to the creosote.’

‘What?’

‘When Petrov lit the fire that day he was killing himself, though he didn’t know it. Creosote is a natural substance. It comes from wood that hasn’t dried long enough. I suspect the chimney hadn’t been cleaned in years and the wood was young, and…’ The inspector raised his palms to the ceiling indicating the inevitable and not uncommon.

Saul Petrov had struck the match that had eventually killed him. It was an accident after all.