On an exceptionally hot and humid July fourth, Dexter Shaw turned a corner and all at once found himself back in the tense days and edgy nights of his youth. Perhaps it was the sight of the nubile young woman in her sleeveless halter top or the drugged-out young man sitting in the hot shade of a white-brick building, a somnolent dog at his side, a cardboard sign between his knobby, scabbed knees, scrawled with the message, "Please Help. Lost Everything."

On the other hand, perhaps it was something else altogether. Confronting the crowds milling through Union Square Park, he felt as if he were a swimmer, far from the teeming shore, guided and controlled by winds and currents seen only by him. He experienced this separation even more keenly as he edged his way into the human surf. Secrets had a way of making you feel alone even in the midst of a jostling throng. It was true. The deeper the secrets went, the more profound the isolation. The murmuring of lovers, the chatter of friends, the morse-code conversations of businessmen on cell phones, mundane all, and yet to him they seemed exotic, so far were they from his own life. Of course, this had been his reality for decades, but today his own anxiety had transformed these differences into knife blades whose edges he felt against his ruddy skin like an immediate threat.

He became aware of a tall, emaciated man with an unkempt beard hiding most of his face moving toward him.

"I am he that liveth, and was dead; and, behold, I am alive for evermore, amen; and have the keys of hell and of death!" the man shouted at Shaw, quoting Revelations. His hollowed-out eyes drilled into Shaw's, as if commanding his attention. "Write the things which thou hast seen, and the things which are, and the things which shall be hereafter!"

Shaw moved away, but the voice, shrill and hard as cement, followed him: "The mystery of the seven stars which thou sawest in my right hand, and the seven golden candlesticks. The seven stars are the angels of the seven churches: and the seven candlesticks which thou sawest are the seven churches!"

It was the voice of war, the herald of doom. Ever since he had gotten word of the pope's illness, he'd known with a chill creeping through his bones, even before the murders began. Unless he could find a way to stop it, the countdown to Armageddon had begun.

The nauseating stench of death filled his nostrils, the sight of spilled blood filled his eyes. Shaking off the visions, he made his way through the crowds at the Greenmarket where, moments later, he spotted the Eastern European. He was a Knight of the Field, an operative involved in wet work-that is to say, killing enemies of his organization, of which Shaw was definitely one. A moment later, he had melted into the throng.

At once, Shaw left the market, went into one of the department stores on the south side of 14th Street. There, he spent the better part of twenty minutes, moving slowly from section to section. The Knight of the Field picked him up in housewares, where Shaw perused a display of kitchen utensils. His tail was patient and, if Shaw's skills hadn't been honed to razor-sharpness, he might not have noticed him at all. The Knight looked different-he had rid himself of his sports jacket, wore instead a neutral-colored Polo shirt. He seemed fascinated by a set of fine china, then once again vanished, only to reappear in men's sportswear at the extreme periphery of Shaw's vision. He never looked at Shaw, not even in his direction. He was very good.

Shaw selected several dress shirts, moved toward the rear of the store where the dressing rooms were located. The Knight of the Field drifted after him, interested because of the emergency exit at the end of the corridor.

The first three dressing rooms were occupied, which suited Shaw's objective. Keeping his eye on the emergency exit, he kept going. The Knight moved behind him, silently closing the gap. Shaw could feel the man's approach, and he lengthened his stride. His pursuer, overcompensating, came at him too quickly.

Shaw spun around, threw the dress shirts into the Knight's face. As he did so, he drew a potato peeler he'd palmed off the display in housewares across the Knight's cheek. Shaw grabbed the Knight's shirtfront, slammed him into the empty dressing room on the right, kicking the door closed behind him. No Knight would follow him to where he met with his son, this he vowed.

"What good is this?" the Knight said, wiping his cheek. "Do you think you can stop us?" He laughed. "It's already too late. Nothing will stop us."

Shaw hit him in the side, just at the end of his rib cage. The Knight bent but did not break. He half turned, drove his cocked elbow into Shaw's chin. He'd aimed for Shaw's throat, but Shaw had just enough room to shift away. Still, the blow made pain explode in his head. The Knight followed up his advantage with a kidney punch. Shaw landed a blow on his sternum.

Beneath the harsh light, their reflections blurred, they fought in silent, intense fashion, striking and blocking like martial artists, feinting and parrying like fencers, using short, sharp, vicious blows dictated by the tiny room.

Until they stood locked together as if in a lover's embrace.

"You're finished," the Knight said. "It's the end."

Freeing one hand, Shaw buried his thumb into the soft spot beneath the Knight's left ear where the carotid artery pulsed. The Knight, seeing his end, fought like a maddened beast, but no matter what he did, Shaw held on, tenacious as a bulldog. At last, the Knight lost consciousness, slipping to the floor.

Shaw took a moment to calm himself while he rearranged his clothes. He thought about what the Knight had said: "It's already too late. Nothing will stop us." Could it be true? he wondered. Could the Knights be further along than even he knew? The possibility chilled him to the marrow. It was now more imperative than ever that he talk seriously with Bravo. Whatever ill feeling stood between them, they must put it aside.

He stepped briskly back into the corridor. Quickly, with a keen and wary eye toward more possible Knights, he exited the store through the employees' entrance on 13th Street.

From there, he plunged into the heart of the Village, turning south onto University Place, then west onto 11th Street. Alone again, he might have slowed down, but instead he hurried on at the same alarmed pace. What breeze had existed in the park had died. A midsummer haze bleached all color from the sky, and the air was freighted, which, combined with the stillness, clung to him with an unwanted intimacy.

So, despite all his precautions, they knew his location. Perhaps not so surprising, considering the meticulous planning behind the concerted attacks of the past two weeks, culminating with Molko's capture. Molko had been tortured and, when that proved fruitless, killed-an hour, perhaps even less, before Shaw had mounted a rescue mission.

Terrible luck. He and Molko had discussed the issue more than six months before the first killing. Molko, to his credit, had accepted Shaw's plan without protest. But within hours of the meeting, Molko had been taken, tortured and killed. Shaw had to assume that the enemy had the second key.

The keys of hell and of death.

He found French Roast, the cafe Bravo had suggested, and went inside. His son hadn't arrived as yet so he asked the pale question mark of a woman at the podium for an outdoor table. At the tiny metal table, he sat in the sun, ordered a cafe' au lait and thought of the Knight of the Field, and of the prophesies of Revelations. He knew a lot about prophesies, far more than most people. "The things which thou hast seen, and the things which are, and the things which shall be hereafter. …" He imagined that the words spewed out by the religious zealot referred to the war footing on which he found himself.