“A guy Emma knows invited us to his apartment in TriBeCa. His parties are great, they say. He works on Wall Street,” he said.

“I don’t know, Steve. I don’t think I want to spend my Saturday night with a bunch of bankers.”

After my week with Harry and his entourage, it didn’t feel like relaxation to be plunged back into his world.

“Right. You’ve got so many other choices, don’t you? That’s why you’re calling me at six o’clock. Come on, it’ll be fun.”

When the sun had set and the lights had gone on in Union Square, casting a glow over the rooftops, I went into the bathroom. I opened a medicine cabinet above a jar of seashells that Rebecca had collected on a vacation we’d had in Cape Cod. I poked among the lotions and deodorants, behind the Ambien that she’d sometimes taken to help her sleep. I found a bottle full of orange ovals-30-milligram tablets of Adderall. Doctors shouldn’t self-medicate, especially not with amphetamines meant to treat attention deficit disorder, but Steve did and sometimes I did, too. At that moment, I craved anything that would blank out the thoughts in my head.

By the time I’d hailed a taxi downtown, my skin was prickling and a sheen of sweat had broken out on the backs of my hands as the amphetamine salts filtered into my blood, tampering with the norepinephrine and dopamine inside my brain. My mouth was dry and I felt the worry of the past few days drop away, leaving a light-headed fascination with the colors and shapes around me. All of the emotional clamor, the buzz of discomfort, grew muted. The discordant groans of the taxi’s air conditioner congealed into a pleasing harmony. I lowered the window as we shot along Broadway and the lights streamed behind us like a vapor trail in blue sky.

I pushed fruitlessly at the buzzer on the metal door to the building for five minutes before a couple rolled down the stairway on their way out and admitted me. It was obvious why I’d been ignored when I reached the tenth floor of the building and heard the roar of voices from inside the apartment. It was a vast multifloored loft with white-painted iron columns and a crush of guests shouting over hypnotic music being mixed on an Apple laptop by a DJ. Urban wealth was on display everywhere, from the canvases of rusting bridges and desolate landscapes on the walls to the black-uniformed waiters pouring Krug champagne into flutes. I walked out through the doors onto a terrace with a glittering view of nearby towers and, in the distance, City Hall. Steve was standing in a knot of people, and I walked up to him.

“So you made it. Ben, this is Lucia,” he said.

The young woman by him smiled. She was pretty-dark cropped hair, mascara, and gleaming eyes. She wore a silk dress, and the amphetamines made the straps over her shoulders appear to sparkle in the light.

“Great to meet you,” I said, feeling her soft hand in mine.

“Isn’t this apartment awesome?”

“Amazing.”

“It’s Gabriel’s. He’s over there with Josh.”

She pointed to a corner of the balcony where two men were talking. The man she indicated had a ruddy face, a flat jaw, and alert eyes. He seemed amused by the whole event, as if he were a guest rather than the host.

“I’m going to find a drink. Can I get you one?” I said.

Later on, back at her apartment in the East Village, after she’d gone to sleep, I stood at her bedroom window overlooking a dark alley and stared at the brick wall opposite. It was two a.m. and the Adderall was wearing off, making me shaky and paranoid. I remembered my walk on the beach, Harry telling me how he’d lost everything in the crash, and shivered, my faith in him evaporating along with the drugs. He’d told me he wouldn’t harm himself. Why should I trust him?I thought.

Hot water cascaded over my head and down my body on that Sunday morning as I stood in the shower at the gym, trying to absorb the news. I’d just watched it on television, the thing I’d feared. I’d left Harry in what I’d believed was a stable condition, and he had taken his own life. If I’d stuck with my instincts-the treatment in which I’d believed-instead of giving way to Duncan, I could have saved him. I thought of Nora and the distress she must now be in. After all she’d been through to save him, Harry had abandoned her. How could I face her again?

After a few minutes, I turned off the faucet and stepped out of the shower to dress. The treadmill runners were still panting on their machines as I’d been half an hour before, oblivious to the outside world. Walking out of the gym, I saw the same spring scene-the chess players on the sidewalk, a couple walking a dog, an old lady talking to a doorman-but my pleasure in it had gone.

Back home, I lay on my bed for a minute, thinking about Harry’s death and what it meant for me. I couldn’t talk to Rebecca; I didn’t want to worry my father in his convalescence; I couldn’t face calling Episcopal. Reminding myself that I advised patients not to wallow in their misery, I got up and paced my living room for a while. Then I decided that I had to find out exactly what had happened. Felix, I thought. He’d know. I looked through my jacket for my phone and scrolled through the Calls Received list to the previous week. There was the cellphone number from which he’d called me to fix the return trip on Harry’s jet. Pushing the key to redial, I waited.

“Lustgarten,” a voice said smoothly and evenly after two rings.

Had it been anyone else, and I hadn’t heard the sound of raised voices in the background, I would have thought it was the tone of someone having a relaxed Sunday afternoon. By his standards, however, he sounded edgy.

“Felix, this is Ben Cowper.”

“Ah, Dr. Cowper. How are you?”

“Fine, thanks. I’m sorry to disturb you. It sounds as if you’re busy.”

“Just a little, yes. Could you hold on a minute? I’ll be right with you.”

“Sure,” I said.

He put his hand over the phone, but I could hear his muffled voice call across a room.

“Andrew! … Andrew! Tell him he’ll have to wait. We’ll have a statement in ten minutes.… No, I don’t care. I don’t care if it’s God Almighty.”

There was a rustle as Felix removed his hand and spoke to me.

“Sorry about that. The roof’s fallen in, as you might expect.”

“Are the papers calling?” I asked densely.

“A few. That happens when the chief executive of a Wall Street bank dies violently. The vultures circle.”

If I’d been thinking in that moment, if my brain hadn’t been frozen with shock, I would have caught it. Chief executive, he’d said, not former chief executive. But I pressed on with my questions blindly, and it took another few seconds for Felix to deliver the news unambiguously.

“How’s Mrs. Shapiro coping?”

“Nora’s in quite a state, very traumatized. She’s with the police now. She thinks she can get Harry out on bail. Best of luck, I say.”

“Get him out? From where?”

“Out of jail, I mean. Where else?”

“But he’s dead, isn’t he? I saw it on the news.”

Felix made a strained gurgling sound, half mirth and half horror, at my words. Then he told me. The peculiar thing is that when I first heard the words, my first, instinctive reaction was relief. It turned out I hadn’t let my patient commit suicide after all. I’m not going to kill myself, he’d promised me on the beach in East Hampton, and he’d told the truth-just not the whole truth.

“Harry?”said Felix. “No, Harry’s absolutely fine, apart from being under arrest for murder. It’s Marcus Greene who’s dead. Harry shot him last night.”

The Riverhead Correctional Facility loomed from the mist in the cold morning. I saw a couple of trailers set back in the woods off the Long Island Expressway and the eyes of a startled deer, then I was pulling up to the security gate. It was a gloomy place, six or so floors high with a few narrow slits in the walls to let in light. The walls were covered with rolls of shining razor wire, one piled on another, and patterns were molded on its facade in a halfhearted effort to make it less drab. Don’t get yourself locked in here, the building said. The blue-uniformed guard glanced at my license and waved me on.