“How, then?”

“They have better information about McCann than we do. Somehow. Maybe he’s done business with them. They have his address, at least. Maybe that’s why the door was unlocked. Like Keever’s door was unlocked. Maybe Hackett has already been here once this morning.”

Something in her voice.

Reacher picked up the Ruger and checked the chamber and dropped the mag. Brassy nine-millimeter rounds winked at him. But not enough brassy nine-millimeter rounds.

The mag was one short.

He sniffed the chamber. Sniffed the muzzle.

The gun had been fired.

Chang said, “They didn’t want us to talk to McCann. There were two ways of stopping us. They chose both.”

Reacher checked Hackett’s pulse. In his neck. It was there, but slow. Deeply unconscious. Or comatose. Was there a difference? Reacher wasn’t sure.

Chang said, “We should assume reinforcements sooner or later.”

Reacher said, “This guy could tell us things.”

“We don’t have time.”

“So at least let’s get what we can.”

They got a fancy cell phone, as thin as Chang’s, and a rental car key, and a hotel key card, and eighty-five cents, and a wallet, all from the pockets, and a Heckler & Koch P7, from the holster on the back of the belt. The P7 was small enough to hide, but big enough to use. It shared the same Parabellum rounds as the Ruger, which was logistically sensible. The wallet contained more than a hundred dollars in cash, and a California driver’s license, and a bunch of credit cards. Chang kept the cell phone, for the call log, and Reacher kept the cash, for future expenses, and the P7, for a number of reasons. They wiped what they were leaving behind, and everything else they had touched. They put their loot in their pockets.

Chang said, “Do we need anything else?”

Reacher took a last look around.

He said, “One more thing, perhaps.”

“Which would be what?”

“I think we can forget about organic food and honey bees. Look at this place. There’s sugary breakfast cereal and factory milk. And two candy bars. That’s what he eats. He wears polyester pants. He doesn’t care what he puts in his body and he’s not a tree-hugger. Therefore the LA Times article he reacted to was the Deep Web thing. About the internet. Which would make total sense, with all these computers.”

“You want to take a computer?”

“Did you hear what the neighbor lady said? Before she closed her door?”

“She said she thought Peter installed his computers himself. You hadn’t convinced her. It was a very polite parting shot.”

“She got the words right. Computers are installed, are they not? And she called him Peter. I would have expected an old lady like that to call him Mr. McCann. They must be good friends. Like long-time neighbors sometimes are. In which case maybe they talk about personal matters. And if she knows about computers, maybe he’s told her what’s on his mind. Because she’d understand.”

“We don’t have time to ask her. There could be more of these guys in this building at any minute. And then the cops.”

“I agree,” Reacher said. “We don’t have time to ask her. Not here, anyway. Therefore she’s the extra thing I want to bring with us. The neighbor. We should take her out for a cup of coffee. Away from here. And we should ask her there.”

It was not a fast process. Not a high-speed getaway. There was some skepticism. Some reluctance. In the end Chang had to play the FBI card, literally. Then there was a search for a coat, even though they told her the weather was warm. But it was a matter of manners. She said she wasn’t completely old-fashioned. She wouldn’t insist on gloves and a hat.

Then came the long, unsteady walk down the steep flights of stairs, and out to the street, where it was the Town Car that overcame her last real reluctance. Its gleaming black paint and its driver in his neat gray suit finally sealed the deal. It was governmental. She had seen such cars on the evening news.

Then came Reacher’s search for the right kind of place. Many pleasant candidates were rejected. Finally one was chosen, a traditional Chicago coffee shop, perhaps discreetly updated by a respectful grandson and heir. It had a pleasant atmosphere as well as a full roster of all the required virtues. Which were nearby parking for the Town Car, and inside seating, and a TV screen on the wall.

McCann’s neighbor seemed happy with it. Maybe it reminded her of the places she used to frequent. She folded her bony self into a booth, and let herself be hemmed in by Chang, who slid in next to her. Reacher sprawled on the opposite bench, sideways, as unthreatening as he could be.

All-around introductions revealed her name to be Mrs. Eleanor Hopkins, widow, previously a wife and a laboratory researcher at the university, not only technically literate, but the technical literature with which she was familiar was written, she said, in a very small number of very small ways, in some of the cracks and the edges, by herself, or by people she knew. Or knew of, or might have known of, if she had taken some other job at some other time. She said her career had overlapped an interesting period, in terms of technical progress.

Then she said Peter McCann had lived in her building for a good many years, and they had grown close, in a gruff and occasional and good-fences kind of a way. She said she had last seen him three or four weeks ago. Which often happened. Which was not a cause for concern. She went out very rarely, and it would be a matter of sheer coincidence if she met him in the hallway. And he was gone a lot, anyway, often for days at a time. She had no idea where. She had never inquired. She was his neighbor, not his sister. Yes, he was an unhappy man. Things often turned out badly.

The TV on the coffee shop wall was tuned to local news. Reacher watched it in the corner of his eye. Mrs. Hopkins ordered coffee and a slice of cake, and Chang told her it was possible Mr. McCann had gotten himself into some kind of trouble. Of a sort no one knew. Did she?

She didn’t.

Reacher asked, “Did he seem obsessed about something?”

Mrs. Hopkins asked, “When?”

“Recently.”

“Yes, I would say he did.”

“For how long?”

“About the last six months.”

Outside there were distant sirens, and the dull beat of helicopter blades, maybe a mile away. Reacher asked, “Do you know what Mr. McCann’s problem was?”

“No, I don’t. We spoke very little of personal matters.”

“Was it connected to his son?”

“It might have been, although that tended not to be an up-and-down situation.”

The TV screen showed a helicopter shot of green lawns. Trees. A park.

Reacher asked, “What was the issue with his son?”

Mrs. Hopkins said, “He didn’t talk of it in detail.”

“Did you know he hired a private detective?”

“I knew he intended to take concrete steps.”

“About what?”

“I don’t know.”

“Did you and he talk about technical matters? Given your background and his evident interest?”

“Yes, we talked frequently about technical matters. Over coffee and cake, sometimes. Like this. We explored the issues together. We rather enjoyed it. I helped him grasp the basic structures, and he helped me understand the uses to which they are now often put.”

“Was his obsession a technical obsession?”

“I think not at its core, but there were technical aspects.”

“Was it something to do with the internet?”

On the TV, under the unsteady green picture, was a ticker-tape ribbon, with the words Shooting Victim Found in Park.

The old lady looked up and said, “By a dog walker, I expect. That’s how it usually happens, I think. In parks.”

Reacher said, “What was McCann’s interest in the internet?”

“There were aspects he wanted to understand. Like most laymen he thought of things in physical terms. As if the internet was a swimming pool, chock-full of floating tennis balls. The tennis balls representing individual web sites, naturally. Which is wrong, of course. Web sites are not physical things. The internet has no physical reality. It has no dimensions, and no boundaries. No up or down, no near or far. Although one might argue it has mass. Digital information is all ones and zeroes, which means memory cells are either charged or not charged. And charge is energy, so if one believes Einstein’s e=mc2, where e is energy, and m is mass, and c is the speed of light, then one must also believe that m equals e divided by c2, which is the same equation expressed differently, and which would imply that charge has detectable mass. The more songs and the more photos you put on your phone, the heavier it gets. Only by a trillion-billionth of the tiniest fraction of an ounce, but still.”