Gamache felt his cheeks grow cold. He looked up from the photograph into the glowing eyes of Agent Cohen.

Then Armand took off his glasses and looked from Beauvoir to Lacoste.

They were staring at him in triumph. And for good reason.

“Voilà,” said Lacoste, putting her finger right onto the churlish face of the third man in the picture. “The connection.”

It was Gerald Bull.

Gamache took a deep breath, trying to take it in. “Guillaume Couture knew Gerald Bull.”

“More than knew him, sir,” said Agent Cohen. “The picture’s from Dr. Couture’s obit. Not the one in the newspaper, but the one in the McGill Alumni News.”

“Guillaume Couture went to McGill?” asked Gamache.

“No. He graduated from the Université de Montréal,” said Cohen. “But he worked at McGill.”

“In what department?” Gamache asked.

“Dr. Couture was a mechanical engineer,” said Chief Inspector Lacoste. “But he was seconded to the physics department, to work on the High Altitude Research Project.”

“HARP,” said Adam Cohen, leaning back, then deciding that was far too casual, he sat forward again. “The forerunner of Project Babylon.”

“Antoinette’s uncle worked with Gerald Bull,” said Gamache.

CHAPTER 26

Dinner was served, starting with parsnip and apple soup, with a drizzle of walnut-infused oil on top.

“Olivier gave me the recipe,” said Reine-Marie, turning down the light in the kitchen.

Candles were lit, not so much to create a romantic atmosphere for herself and Armand, and Isabelle and Jean-Guy and young Mr. Cohen. It was for the calm that came with twilight, and tea lights, and the small flickering flames. If the topic of conversation was harsh, at least the atmosphere could be gentle.

They’d returned to the Gamache home for dinner, and to continue what they’d started in the Incident Room.

“Was there any evidence in Antoinette’s house of her uncle’s association with Gerald Bull?” Armand asked.

“Nothing,” said Jean-Guy. “In fact, there was no evidence of her uncle at all. Nada. Not a photograph, not a card. No private papers. If we didn’t know Guillaume Couture was Antoinette’s uncle and had once lived in the place, we’d never have discovered it in that house.”

Gamache took a couple of spoonfuls of soup. It was smooth and earthy and just a touch sweet.

“Delicious,” he said to Reine-Marie, but his mind was elsewhere.

“Some people aren’t nostalgic,” Lacoste said. “My father’s like that. He doesn’t keep papers or letters.”

“Maybe Antoinette just wanted to make the house her own,” said Jean-Guy. “Heaven knows she was self-involved enough. Her uncle’s things might not have been welcome in the seigneurial home.”

“But not even a photograph?” said Reine-Marie. “They were close enough for him to leave her his home and she didn’t keep anything belonging to him? Seems like a purge.”

Armand agreed with Reine-Marie. It suggested a cleansing far deeper than simply making a place her own.

“Maybe that’s what the killer was doing,” said Isabelle. “Maybe he wanted to erase all evidence of Dr. Couture and his connection to Gerald Bull.”

Gamache remembered his conversation with Mary Fraser earlier in the day. And the file the CSIS file clerk was trying to conceal. But why hide a file on Gerald Bull? Everyone expected her to have one of those.

She was trying to hide the name on the file because it was unexpected. And Gamache thought he knew what it said. He’d been wrong. It wasn’t Gerald Bull in that dossier, it was Guillaume Couture.

“More likely the killer was looking for something he thought Dr. Couture would have in his home,” said Beauvoir.

“The plans for Project Babylon,” said Lacoste. “Is that why Antoinette was killed? For something she never even knew she had?”

“But why would Guillaume Couture have had the plans?” Beauvoir asked. “I can’t imagine Gerald Bull would trust anyone with them.”

“Maybe Dr. Couture stole them from Bull,” Lacoste suggested.

“Okay, let’s say he stole them, then what?” said Beauvoir. “Couture just hides them in his home. Why not sell them if they were that valuable?”

“Maybe he wanted to make sure no other gun was ever built,” said Cohen.

“Then why not destroy the plans?” asked Beauvoir. “Why keep them?”