“Chief Inspector Lacoste asked me to look into Antoinette Lemaitre’s family. I tried to send what I found, but the Internet connection here is so weak I decided to bring it down myself to make sure it arrived.”

“He gnawed through his chain,” said Beauvoir, leading everyone over to the conference table.

Gamache sat down and looked from one to the other to the other, finally settling on Isabelle.

“What have you found?”

She leaned forward. “The home Antoinette Lemaitre was living in was in her name, but before that it belonged to her uncle.”

Gamache nodded. He knew that. Brian had told them.

Armand noticed that in front of Agent Cohen there was a page, facedown.

Cohen, Gamache realized, had more than a little bit of the dramatist about him. He must have studied under Jean-Guy Beauvoir.

“Guillaume Couture’s family was from the area,” Agent Cohen reported. “He built the house on some of the land they owned. There were no other relatives. He retired in the early 1990s.” Cohen’s fingers moved to the edge of the paper. “He died in 2005. Cancer. But before he retired he held a fascinating job.”

“He was an engineer,” said Gamache. “Antoinette said he built overpasses. Not dull, but not what I’d describe as fascinating.”

Adam Cohen turned the page over.

It was a grainy black-and-white photograph blown up from a smaller image. It showed a group of men standing in what looked like a tube.

Gamache put on his glasses and leaned closer.

“That,” Adam Cohen pointed, “is Guillaume Couture.”

The nondescript man grinned, almost maniacally, into the camera. His hair was lank and he wore glasses with thick black frames and an ill-fitting suit and tie. Two men stood on either side of him. The one in a cap was caught looking down and away from the camera, while the other appeared disinterested, even disdainful. Impatient.

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.”