“Forget the files. It all started with Aqueduct thirty years ago or more. Somehow Arnot was involved. The company went under, but maybe it didn’t disappear. Maybe it just changed its name.”

Jérôme looked up at him. “If I leave, there’s no saving Aqueduct. They’ll dismantle it all until there’s no trace.”

“Go. Get out. Find out what became of Aqueduct.”

*   *   *

“They’re trying to save the files,” said Lambert. “They know what we’re doing.”

“This isn’t some outside hacker,” said Francoeur.

“I don’t know who it is,” said Lambert. “Charpentier?”

There was a pause before Charpentier spoke. “I can’t tell. It’s not registering properly. It’s like a ghost.”

“Stop saying that,” said Francoeur. “It’s not a ghost, it’s a person at a terminal somewhere.”

The Chief Superintendent took Tessier aside.

“I want you to find out who’s doing this.” He’d dropped his voice, but the words and ferocity were clear. “Find out where they are. If not Gamache, then who? Find them, stop them, and erase the evidence.”

Tessier left, in no doubt about what Francoeur had just ordered him to do.

*   *   *

“You OK?” Gamache asked Nichol.

Her face was strained, but she gave him a curt nod. For twenty minutes she’d led the hunter astray, dropping one false trail after another.

Gamache watched her for a moment, then returned to the other desk.

Aqueduct had gone bankrupt, but as so often happened, it was reborn under another name. One company morphed into another. From sewers and waterways, to roads, to construction materials.

The Chief Inspector took a seat and continued to read the screen, trying to figure out why the Chief Superintendent of the Sûreté was desperate to keep these files secret. So far they seemed not simply benign, but dull. All about construction materials, and soil samples, and rebar and stress tests.

And then he had an idea. A suspicion.

“Can you go back to where we tripped the first alarm?”

“But that’s nothing to do with this company,” Jérôme explained. “It was a schedule of repairs on Autoroute 20.”

But Gamache was staring at the screen, waiting for Dr. Brunel to comply. And he did. Or tried to.

“It’s gone, Armand. Not there anymore.”

“I have to get out, sir,” said Nichol, rattled into courtesy. “I’ve stayed too long. They’ll find me soon.”

*   *   *

“Almost there,” Charpentier reported. “Another few seconds. Come on, come on.” His fingers flew over the keys. “I’ve got you, you little shit.”

“Ninety percent of the files are destroyed,” said Lambert from across her office. “Not many places he can go. Do you have him?”

There was silence, except for the rapid clicking of keys.

“Do you have him, Charpentier?”

“Fuck.”

The clicking stopped. Lambert had her answer.

*   *   *

“I’m out,” said Nichol, and sat back in her chair for the first time in hours. “That was too close. They almost got me.”

“Are you sure they didn’t?” asked Jérôme.

Nichol lugged herself forward and hit a few keys, then took a deep breath. “No. Just missed. Christ.”

Dr. Brunel looked from his wife to Gamache to Nichol. Then back to Thérèse.

“Now what?”

*   *   *

“Now what?” Charpentier asked. He was pissed off. He hated being bested, and whoever was on the other end had done just that.

It’d been close. So close that for an instant Charpentier had thought he had him. But at the last moment, poof. Gone.

“Now we call in the others and look again,” said Chief Inspector Lambert.

“You think he’s still in the system?”

“He didn’t get what he came for.” She turned back to her monitor. “So yes, I think he’s still there.”

Charpentier got up to go into the main room. To tell the other agents, all specialists in cyber searches, to go back in. To find the person who’d hacked into their own system. Who’d violated their home.

As he closed the door, he wondered how Inspector Lambert knew what the intruder was looking for. And he wondered what could be so important to the intruder that he’d risk everything to find it.