He did not feel much different from the way he had felt in September, except that he tired more easily now, and he slept longer than he had in those days.

When he looked in a mirror, he noticed only small changes. A slight bloat. Sometimes a persistent unhealthy flush in his cheeks, at other times a gray-blue paleness of the skin under his eyes.

He became impatient not only with his progress up the waiting list but also with Samantha. Sometimes she tested his forbearance.

For one thing, he felt that she had too much confidence in the organization that compiled the list and selected the recipients.

If Ryan had managed his business with the kind of unwarranted assumptions and the tolerance for bureaucratic inertia that he saw in this particular medical community, he would not have become a wealthy man. Since lives were at stake here, he argued that these gatekeepers should be more-not less-efficient than he had been while building a social-networking empire on the Internet.

She would listen to little complaining on the subject before reminding him that he had promised to weather this waiting period with a relaxed attitude. He had pledged not to try to handle what in truth he could not control, but to let it unfold as it would.

“Dotcom, you worry me,” she told him now. “This restlessness, these spells of anger. This isn’t good. It doesn’t help you. You’re wound too tight.”

Week by week, Ryan developed more exotic strategies to survive, investigating all manner of alternative-medicine treatments that might supplement what any cardiologist could do for him, everything from rare substances obtained from the spores of rain-forest ferns to psychic healing.

With sympathy, reason, and humor, Samantha provided a reality check to each treatment scheme that he considered adopting. Although he knew she was right, sometimes her acerbic humor seemed to be cold sarcasm, her reason mere pessimism, and her sweet sympathy insincere.

Ryan suspected that his sour moods and his frequent spells of restlessness and agitation were caused by his medications. A review of the side effects listed for each drug confirmed his suspicion.

“I’m sorry, Sam,” he told her more than once. “It’s these damn drugs. I’m not myself. Next thing, I’ll be growing hair on my palms and howling at the moon.”

He knew that he was exhausting her, that her work on the novel had come almost to a halt. He began to give her more time to herself, though she protested that she would be there for him all day, every day, until he was restored to full health, with a new heart.

On December 12, they had dinner in a restaurant where white tablecloths, Limoges china, crystal, and waiters in white jackets set both a mood and a standard.

This wasn’t one of those Newport Beach high-end meat markets that layered on the style but catered to upscale singles who chose their dinner companions from the opportunities at the bar. Here the clientele was older, quieter, with at least a veneer of class, often with that old-money charm and grace that made even true class seem somewhat tacky by comparison.

Between the appetizers and the entrees, Ryan told Samantha about Dr. Dougal Hobb, a prominent cardiologist and cardiovascular surgeon with offices in Beverly Hills.

“I think I might switch to him,” he said.

Surprised, she asked, “What’s wrong with Dr. Gupta?”

“Nothing. He’s fine. He’s all right. But Dr. Hobb is so highly regarded. He’s really at the top of his profession.”

“Will it affect your position on the waiting list?”

“No. Not at all.”

“What does Forry Stafford say?”

“I haven’t discussed it with him.”

“Why not? He recommended Dr. Gupta.”

In any restaurant, he and Samantha usually preferred a table in a corner, to allow them greater privacy, but on this occasion they sat at the center of the establishment. The elegant room sparkled, a treat for the eyes, and it lay all around them.

“I will call Forry,” Ryan said. “I just haven’t yet.”

“Dotcom, is this just change for the sake of change, just more restlessness?”

“No. I’ve given this a lot of thought.”

Assisted by a busboy, their waiter arrived with the entrees and presented each dish with sufficient flourishes to confirm the excellence of the service without descending to showiness.

As they began to eat, Ryan changed the subject. “You’re so lovely tonight. Everyone is taken with you, the center of attention.”

“Well, we are at the center of the room, you’ll notice. And I suspect most of these people know who you are, which makes me very much the supporting act.”

She let him lead her down conversational byways, but in time she returned to Hobb. “Before you leave Dr. Gupta, talk to Forry.”

“I will. But they don’t get better than Dougal Hobb. I even had a complete background done on him.”

“Background?”

“By an extremely dependable security firm. To see if he’s had any malpractice suits filed against him, personal problems of any kind.”

Her blue-green eyes did not darken, but her mood underwent a tidal change. “You had a private detective scope him out?”

“It’s my life on the line, Sam. I want to be sure I’m in the best possible hands.”

“Forry is your friend. He sent you to the best. He wants the best for you.”

“Dr. Hobb has never had a complaint lodged against him, let alone a legal action.”

“Has Dr. Gupta?” she asked.

“I don’t know.”

“I’m sure he hasn’t.”

“I don’t know. But listen, Dr. Hobb’s private life is without a stain, his finances are in perfect order, his marriage is rock-solid, his-“

Putting down her knife and fork, she said, “You’re scaring me.”

He raised his eyebrows. “Why?”

“Can’t you hear yourself? You’re trying to handle this, take charge, but it’s fundamentally not yours to take charge of.”

He answered her concern with a sheepish look. “Be to do. It’s not just the cute name of a company. It’s a life philosophy. Taking control is a hard habit to break.”

“And trusting people is a difficult habit to establish, Ryan, not least of all for people like you and me, considering where we come from.”

“You’re right. All right. I know.”

“We can shape our fates,” she said, “but we can’t control them. You can’t control death. You need a team here. You need to make these decisions only after consultation.”

“I’m consulting with you right now.”

She neither broke eye contact nor replied.

“Okay,” he said. “You’re right. I won’t do anything until I’ve talked to Forry and Dr. Gupta. And to you.”

She drank some of the Cabernet. She put down the wineglass. She surveyed the glittering room, requiring other diners to look away from her.

Her attention on Ryan once more, she said, “Sweetie, trust the people who care for you. Trust me especially because I understand you so well, so very well, so entirely-and I love you.”

Moved, he said, “I love you, too.”

“If you knew me as completely as I know you,” she said, “you might not love me.”

“Impossible. What a thing to say.”

“No, it’s true. Human beings are such knotted, desperate pieces of work-it’s a rare thing to know one completely, to the core, and still love him. Or her. I don’t need dessert. Do you?”

She had so riveted him that her change of subject did not at first compute, and he stared at her as though she had switched from English to some obscure Russian dialect.

Then: “Oh. No. I don’t need dessert.”

“Maybe after the wine, a double espresso.”

“That sounds good.”

She said no more about Dr. Hobb or about the knotted, desperate nature of humanity, but spoke of happier things.

Over the espresso, she favored Ryan with an affectionate smile that gladdened him, and as chandelier light danced in her eyes, she said, “See, Winky, you could have taken me to the farthest corner of the room, and even in that privacy, I wouldn’t have scalped you or even boxed your ears.”

Little more than one day later, on December 14, at home alone, as he awaited the sleep that for hours had eluded him, comforted by the glow of a bedside lamp that he was loath to turn off these days, Ryan suffered a sudden breathing problem.

He inhaled without relief, as if the air he took in were going elsewhere than to his lungs, although his belief that he was drawing full breaths might have been a misperception. An immediate sense of suffocation overcame him, a choking anxiety, and he could not stave off panic.

When he pushed up from the mattress, he was whirled into such a dizziness that the bed seemed to be on a carousel, and he fell back onto his pillows, gasping, soaked in a copious and instant hot sweat.

In that moment, a light-year was defined as the distance between him and the telephone on the adjacent nightstand. He could see it but did not have enough knowledge of Einsteinian physics to be able to make the epic voyage.

The paroxysms lasted only a couple of minutes. But when he could again draw breath easily, air had never tasted sweeter.

For a while, he was reluctant to move, afraid that movement would trigger another event, the same or worse. When at last he sat up, swung his legs off the bed, and stood, he discovered that his ankles were badly swollen.

Although he took his medications faithfully and punctually, he was retaining water.

Standing beside the bed, for the first time in months he heard a tapping, someone gently rapping, rapping at a window or a door.

Panic had subsided, but fear remained. The sweat that sheathed him had gone cold.

Turning, he searched for the source of the sound, cocked his head toward the insistent metronomic tap. He took a few steps in one direction, but then took a few in another, pausing repeatedly to listen.

He moved from the bedroom into the sitting room, into the bedroom once more, and then into the black granite and the gold onyx and the stainless steel and the mirrored walls of his bathroom. In that maze of reflections, the rapping continued, as loud there as everywhere else.

For a moment Ryan believed that the sound came from underfoot, that its ubiquitous nature-always the same volume, the same timbre in room after room-indicated a source beneath the floorboards, one that, incredibly, was mobile and tracking him.

But then he recalled that the floors were lightweight concrete, which had been specified for the very purpose of sound suppression. No floorboards existed to be torn up. No hollow space lay underfoot, through which the source of the sound could pursue him.

He looked at the ceiling, the only other plane universal to these third-floor rooms, and he thought of the attic overhead. He entertained the possibly lunatic, certainly antic image of a stalker above him, some phantom who had traded opera-house cellars for higher haunting grounds, electronically monitoring Ryan’s position for the purpose of tormenting him with the rapping, the soft rapping, the soft rap-rap-rapping, only this and nothing more.

That absurd speculation lasted mere seconds, for abruptly Ryan realized that the sound arose from within him. Although it was not the classic lub-dub of the blood pump, it was associated with those rhythms. It was an ominous throb born of his heart’s malfunction, not a gloved knuckle against a door, not a fat moth against a windowpane, but a blood-and-muscle sound, and if it failed to fade away this time, as it had faded before, if the rapping kept on long enough, it would be answered, not by Ryan, but by Death.

He took a shower, as hot as he could endure, hoping to chase the cold from his bones. The quiet rap came and went and came again, but he did not wipe the steam from the glass door in expectation of an intruder’s grinning face.

In his closet, which was as large as a room, as he dressed, the rapping might have come from behind any cabinet door, from within any drawer, from behind any pane of the three-sided mirror, but Ryan no longer needed to search for the source.

The scheduled superstretch from the limousine service arrived at eight o’clock. The driver called himself Naraka, though Ryan didn’t know if that was his first name or his last.

As they pulled away from the house, the internal knocking fell silent and never once resumed all the way from Newport Coast into distant Beverly Hills.

Two days previously, prior to dinner with Samantha, Ryan had secured an emergency appointment with Dr. Dougal Hobb. Following Sam’s disapproval, he considered canceling it, but left the final decision for the last minute, for this morning.

Considering the frightening problem with his breathing in the night and the belated realization that the occasional knocking was a muffled internal sound, he believed that a conversation with Hobb would be prudent.

Ryan did not inform Dr. Gupta or Forry Stafford of his decision. He did not even tell Samantha.

His only consultation was with his instinct for survival, which told him that meeting Hobb was not merely advisable but as essential to the preservation of his life as a flame-free stairway would be indispensable to a man trapped in the inferno of a burning high-rise.

Dr. Dougal Hobb did not maintain his offices in one of the gleaming skyscrapers that lined Wilshire Boulevard, as did many other physicians. His practice occupied an entire three-story building on a quiet street on the edge of the Beverly Hills business district.

This elegant neoclassic structure-white with a black slate roof, embraced by old magnolia trees that fanned their giant spade-leaf shadows onto its walls-looked more like a private residence than like a place of business. Only a discreet brass plaque beside the front door identified the premises: D. HOBB, M.D.

Three doors opened off the foyer, and the one on the right was labeled APPOINTMENTS.

This proved to be a waiting room with a Santos mahogany floor on which floated an antique Persian carpet, a nineteenth-century Tabriz, which glowed as if woven from gold. The comfortable chairs and stylish end tables suggested that patients here were treated like guests.

Ryan could not identify the classical music that played at low volume, but he found it soothing.

The receptionist, an attractive woman in her forties, was not wearing the surgical scrubs or the shapeless exercise suits that were all but standard in most medical offices these days, but a beige knit suit of designer quality.

Both the receptionist and the nurse, Laura, who took Ryan’s preliminary medical history in a small conference room, were well-spoken, professional, efficient, and warm in their manner.

Ryan felt that he had sailed out of a storm into a sunny harbor.

Laura, in her twenties, wore an oval locket suspended from an intricately braided gold chain. The enameled medallion on the front of the locket featured a stylized gold-and-red bird with spread wings, rising.