And then she laughed, a happy sound, as if certain her joke didn’t apply to her, as if certain her daughter’s marriage would last forever.

Chang asked, “Would this evening be more convenient?”

“May I know what it’s about?”

“Your brother Peter.”

“Oh dear, I’m so sorry, but I think you might have wasted a trip. He isn’t here. He didn’t come. We expected him, obviously, but it’s a long flight. How do you know Peter?”

“We should get into that later this evening. If that’s convenient. Because right now we’re holding you up. And we’ve taken far too much of your time already. We should let you get back to your guests.”

McCann’s sister smiled appreciatively, and started to turn away. But a new thought struck her, and she turned back, different. She said, “Is Peter in trouble? Are you police officers?”

Chang did the only thing she could, as a woman with a code, which was to ignore both questions completely, and respond with a statement that resembled an answer. She said, “We’re private investigators.”

“Did Keever send you?”

“Ma’am, now we really need to talk. But we can’t pull you away from all of this.”

“Is Peter in trouble?”

Chang did the same thing again. She said, “Ma’am, we’re here to be briefed. Our job is to hear about Peter from you.”

McCann’s sister said, “Come with me.”

They walked through the house to a dark-paneled study, shuttered tight against the sun, with club chairs and a river stone fireplace. They sat down, the women perched almost knee to knee, Reacher leaning back. McCann’s sister asked, “Where should I begin?”

Reacher said, “Tell us what you know about Keever.”

“I never met him, obviously. But Peter likes to talk things through, so during the selection process I felt I got to know all the candidates to some extent.”

“How many candidates were there?”

“Eight to start with.”

“Did the process take long?”

“Almost six weeks.”

“That’s thorough.”

“That’s Peter.”

“How often do you talk?”

“Most days.”

“How long are the calls?”

“Some days an hour.”

“That’s a lot.”

“He’s my brother. He’s lonely.”

“Why did he need a private detective?”

“Because of Michael, his son. My nephew.”

“People say there are issues.”

“That’s the wrong word. That’s a polite way of saying difficult. Which is already a polite way of saying something worse. Michael is the opposite of difficult.”

“What would be the right word?”

“Michael didn’t make it all the way to the end of the assembly line. A couple of things didn’t get bolted on. I try not to blame the mother. But she wasn’t well. She died less than ten years later.”

“Which things got missed?”

“Are you a happy man, Mr. Reacher?”

“Can’t complain. Generally speaking. Right now I feel pretty good. Not in relation to the current part of our conversation, you understand.”

“On a scale of one to ten, what’s the worst you’ve ever felt?”

“About a four.”

“And the happiest?”

“Compared to the theoretical best ever?”

“I suppose.”

“About a nine.”

“OK, four at the bottom and nine at the top. What about you, Ms. Chang?”

She didn’t answer right away. Then she said, “The worst I’ve ever felt would be a three. And I was going to say eight for the best. But now maybe nine. I think.”

She looked at Reacher as she said it, in a certain way, and McCann’s sister caught the glance. She said, “Are you two sleeping together?”

No response.

“Honey, if you’re sleeping together, make it a nine for sure. Always safer. But no higher. Ten gives them performance anxiety. But right now between the two of you we have a swing from either three or four at the low end to a pair of nines at the high end, even though one of the nines is really an eight, but we’re too polite to say so. But you get my drift. You’re normal people. If you swung from two to seven you’d still be normal, but you’d be seen as a little dour and reserved. Understand?”

Chang nodded.

“Now suppose your needle is jammed on zero. Doesn’t move at all. Zero at the bottom and zero at the top. That’s Michael. He was born unhappy. Born without the capacity to be happy. Born without any concept even of what happiness is. He doesn’t know it’s there.”

Chang said, “Is there a name for that?”

“They have names for everything now. Peter and I discuss them endlessly. None of them really fits. I like an old-fashioned vocabulary. I think of it as melancholy. But that sounds too weak and passive. Michael has depth of emotion. Just not range. You feel joy or passion, and he feels the same intensity, but it’s all hammering away down at the zero level. And he’s intelligent. He knows exactly what’s happening to him. The result is endless torment.”

“How old is he now?”

“He’s thirty-five.”

“What are the outward signs? Is he hard to get along with?”

“The opposite. You hardly know he’s there. He’s very quiet. He does what you tell him. He hardly speaks. He sits for days staring into space, chewing his lip, his eyes darting around. Or else he’s on his computer, or fiddling with his phone. There’s no aggression. He never gets upset. Upset would imply an emotional range.”

“Can he work?”

“That’s been part of the problem. He has to work, to qualify for housing. It’s part of the deal. And he can work. There are things he’s good at. But people find him draining. They don’t like to be with him. Productivity goes down. Usually he’s asked to leave. So he’s in and out of the programs.”

“Where does he live now?”

“Right now, nowhere. He went missing.”

At that point the bride-to-be came in, looking for her mother. A thin shirt over her bikini. Peter McCann’s niece. Michael McCann’s cousin. Up close she was still luminous. She glowed. She was close to perfect. Pre-natal care, perinatal care, post-natal care, pediatrics, nutrition, education, orthodontics, vacations, college, postgrad, a fiancé, the whole nine yards. Her assembly line had worked just fine. The American dream. A spectacular result. And she looked happy. Not silly, not giggly, not hyped up, and not an airhead. Just deeply and serenely content. With room at the top for ecstasy. Her needle ran from maybe six to ten. She had gotten everything her cousin hadn’t.

McCann’s sister went back out to the pool with her. She promised to return as soon as she could. Reacher and Chang sat quiet in the darkened den. They heard the sounds of the party, muted by walls and distance. Splashes and yelps and the clink of glasses, and the rolling murmur of conversation. Chang said, “We should call Westwood in LA. We should update him. A deal’s a deal. Plus we’re going to need another hotel.”

Reacher said, “Tell him we need everything he has on the Deep Web. All his notes. Or maybe tell him to come out here to explain it all in person. We might not understand his notes. He can get on a plane. He’s getting the book deal.”

Chang put her phone on speaker and dialed, and she gave the guy the play-by-play, everything that had happened since she last called, from the West Hollywood motel. She mentioned Chicago, the library, the mom-and-pop pharmacy, McCann’s street, McCann’s house, Hackett, the neighbor, the Lincoln Park homicide, the flight to Phoenix, and finally the sister. And then the son, in the long term trapped between zero and zero, and in the short term missing.

Westwood said, “They call it anhedonia. The inability to experience pleasure.”

“The sister makes it sound worse than that.”

“And Keever’s job was to find him and bring him home?”

“We assume so. We didn’t get that far in the story. We were interrupted.”

“I don’t see how the Deep Web or two hundred deaths are involved. This feels like the crime desk, not the science desk. Or one of those human tragedy stories.”