‘Here,’ he shouted, staring into the half doorway. He’d taken it for a broom closet, but now his flashlight showed a set of steep, narrow steps leading up. Shining his light to the top he saw the trap door was closed. Please God, not locked.

‘Let’s go.’ Gamache moved ahead of Beauvoir into the stairway. ‘Come on.’ He looked back, puzzled, as Beauvoir hesitated then entered the dark, narrow space.

The stairs were built for tiny people from a century ago, undernourished Québecois farmers, not the well-fed Sûreté officers of today, wearing outsized winter firefighting clothing. There was barely enough room to crawl. Gamache took off his helmet, and Beauvoir did the same, relieved to be free of the cumbersome piece of equipment. Gamache edged up the narrow steps, his coat scraping the walls. It was black up ahead and their flashing lights played on the closed trap door. Beauvoir’s heart was pounding and his breathing fast and shallow. Was the smoke getting thicker? It was. He was sure he could feel flames at his back and turned to stare behind him, but saw only darkness. It wasn’t much of a comfort. Please, let’s just get out of here. Even if the entire second floor was in flames, that was better than being entombed in the stairway.

Gamache put his shoulder to the trap door and shoved.

Nothing happened.

He shoved again, harder. It didn’t budge.

Beauvoir looked back down to where they’d been. Smoke was seeping under the door below. And the door above was locked.

‘Here, let me through.’ He tried to shove past Gamache, even though a piece of paper wouldn’t get by. ‘Use the axe,’ he said, his voice rising. He could feel his skin tingling and his breathing coming in quick shallow gulps. His head felt light and he thought he might pass out.

‘We need to get out of here,’ he said, hitting the walls with his fist. The stairway had him by the throat and was choking him. He could hardly breathe now. Trapped.

‘Jean Guy,’ Gamache called. His cheek was on the ceiling, his body pressed against it. He couldn’t go forward and he couldn’t go back and he couldn’t comfort Jean Guy, who was panicking.

‘Harder, push harder,’ Beauvoir shouted, his voice rising in hysteria. ‘God, the smoke’s coming in.’

Gamache could feel Beauvoir cramming his body against his in an effort to get further from the smoke and flames.

We’re going to die here, Beauvoir knew. The walls were closing in, dark and narrow, binding and suffocating him.

‘Jean Guy,’ Gamache shouted. ‘Stop it.’

‘She’s not worth it. For God’s sake, let’s go.’ He was shouting and tugging at Gamache’s arm, dragging him back down into the darkness. ‘She’s not worth it. We have to get out of here.’