“I bought one of these for my grandson. My daughter wasn’t impressed. David spent six months urinating in public after that. That child could pee for Canada.”

He then picked up the desk set. Taking out the pens, he studied them, then rummaged through the box until he found the bookends. He turned one over, put it down and picked up the other. By now Lacoste and Beauvoir had joined the elderly scientist, watching as he toyed with the items.

“What are you—” Lacoste began but stopped, not wanting to break his concentration.

They watched as the professor manipulated the items, and then there was a small click. Rosenblatt frowned, then, picking up the two pens, he inserted them into holes at the base of the bookend.

After studying it for a moment, he held it out, as a bright child might who’d made something for Mother.

“Is it…?” Lacoste asked, taking it from him.

“The firing mechanism? I think so,” said the professor, as astonished as everyone else. “Ingenious.”

Gamache stared at the piece in Lacoste’s hand while she turned it over and over and around. It looked nothing like a pen set and bookend now. Just as the pen set and bookend had looked nothing like a firing mechanism.

“How did you know?” asked Beauvoir, taking it from her and also turning it around and around, studying it.

“I didn’t, I just tried. A prerequisite for being a physicist, I think. Good spatial reasoning. But the first clue was the pens, of course.”

“The pens?” asked Beauvoir.

“They don’t work,” Rosenblatt pointed out. “No nibs. They wouldn’t write.”

Lacoste and Beauvoir looked at each other, then over at Gamache, who was staring at the firing mechanism in Beauvoir’s hand. Then he dropped his eyes to the computer screen, where the poem had appeared.

In his line of sight, forming a tableau, were the firing mechanism, the Son My Massacre, John Fleming’s play on Beauvoir’s desk, and the words on the computer:

And what rough beast, its hour come round at last,

Slouches towards Bethlehem to be born?

CHAPTER 31

“The clock is ticking,” Gamache said quietly as he and Rosenblatt took seats at the back of the bistro. “Isn’t it?”

Around them, young waiters set the tables for the dinner service. Out the window, dying leaves shuffled in the wind and rain, and two chipmunks sat up on their haunches, alert.

Were they hearing it too? Gamache wondered. On the wind.

The tick, tick, ticking of time running out.

“Yes,” said the old scientist. He raised a hand and caught the attention of a server. “Chocolat chaud, s’il vous plaît.”

“Have you considered a nice warm apple cider?” Olivier asked. “Please?”

“Sounds good, patron,” said Gamache.

“And one for me too. Nonalcoholic. I’m still recovering from last night,” he said to Armand once Olivier had left. “You know, I ordered a hot chocolate yesterday and they brought an apple cider.”

Professor Rosenblatt extended his hands to the fire in the hearth, rubbing them together as though the warmth was water.

“That was quite a trick,” said Gamache, when the cider arrived. He stirred the drink with the cinnamon stick, the warm apple and cinnamon scent mixing with the musky wood smoke. “Finding the firing mechanism.”

“A trick?” Rosenblatt studied the man in front of him.

They’d left the Sûreté officers to continue their research, galvanized by the findings, and Gamache had brought the elderly scientist to the bistro. People were beginning to arrive for drinks before dinner, but their table was tucked nicely away and few would even notice they were there. To be certain of privacy, Gamache had asked Olivier not to seat anyone too close.

“This isn’t a magic act, you know, monsieur,” said Rosenblatt, as serious as Gamache had ever seen him.

“And you’re not the magician?”

The professor pursed his lips, contemplating. “Do you suspect me of something?”

“What’s in Highwater?”

Now the lips went taut and a stillness came over Rosenblatt. Gamache could almost smell the man’s mind working. It smelled a bit like apple.

Rosenblatt smiled, more with resignation than humor.

“You know about that?”

“Mary Fraser and Sean Delorme went there shortly after seeing the gun,” Gamache explained. “We tracked their cell phones.”

Rosenblatt shook his head. “File clerks.”