At his feet, a torrent of ebbing saltwater tide and freshwater river current raced toward the sea. Overhead, he saw the shadows of a dense frame of piles and timbers – the underbelly of the pier. He stepped onto a final crumbling lip of brick and looked around.

“What took you so long?” said a voice.

Isaac Bell had a split second to train his light on a bearded face, slick with blood, before Harry Frost hurled a pile-driver punch.

WITH FOUR YEARS of college boxing and ten years as a Van Dorn agent, including an investigation in the Arizona Territory disguised as an itinerant prizefighter, and another as a lumberjack, Isaac Bell reacted by rolling with the punch.

Memory speeded up, as if whirled in a turbine. He recalled events too fast to register as they had occurred. In memory, he could see Frost’s fist swinging at him. He could see that he had been caught flat-footed. If he went down at Frost’s feet, he was a dead man. His only chance to live was to make absolutely sure that Frost couldn’t follow up with another blow.

Harry Frost had obliged Bell by knocking him backwards into the Hudson River.

The current was swift, tide and river speeding toward the sea.

Isaac Bell was barely conscious, with an aching jaw and a throbbing head.

He saw Frost scrambling along the narrow shelf of mud that the falling tide had exposed on the shore under the piers. Dodging the pilings that marched from the land into the river, Frost tried to keep up with the current. He scampered like a dog wanting to jump in the water after a ball but afraid of drowning.

The current slammed Bell against pilings in the water. Bell seized hold of one. Less than fifteen feet separated the detective and the murderer. “Frost,” he shouted, gripping the slimy wood, fighting the current. “Give it up!”

To Bell’s surprise, Harry Frost laughed.

Bell had expected howling curses. Instead, the murderer was laughing. Nor was it insane laughter. He sounded almost cheerful when he said, “Go to hell.”

“It’s over,” Bell shouted. “You can’t get away from us.”

Frost laughed again. “You won’t get me before I get Josephine.”

“Killing your poor wife won’t do you any good, Harry. Give it up.”

Frost stopped laughing. “Poor wife?” His bloodied face worked convulsively. “Poor wife?” He raised his voice in an angry cry: “You don’t know what they were up to!”

“Who? What do you mean?”

Frost stared at him across the rushing tide. “You don’t know nothing,” he said bitterly. He shrugged his massive shoulders. An odd smile flickered across his mouth before his expression hardened like a death mask. “Say, look it this.”

Harry Frost bent down and pawed in the mud. He straightened up, holding Bell’s Browning.

“You dropped this when you ran away by jumpin’ in the water. Here you go!” He flung the pistol in Bell’s face.

Bell caught it on the fly. He juggled the muddy grip into his palm and flicked off the safety. “Elevate! Hands up!”

Harry Frost turned his back on the detective, clinging to the piling in the water, and stalked upstream against the flow of the tide.

“Hands up!”

“I’m not afraid of you,” Frost called over his shoulder, taunting. “You are nothing. You couldn’t even take one punch. You ran away.”

“Stop right there.”

“If you didn’t have the belly to take another punch, you sure as hell don’t have the nerve to shoot me in the back.”

Bell aimed for Harry Frost’s legs, intending to slow the man, climb out of the water, and get him. But he was numb with cold. His head was reeling from the punch. It took an act of will to steady the barrel, another to force his finger to curl smoothly around the trigger so he wouldn’t miss.

The gun felt heavy.

“You don’t have the guts to pull the trigger,” Frost flung over his shoulder.

Strangely heavy. Was he losing consciousness? No. It was too heavy. Why did Frost throw it instead of simply shooting him? Why was he daring him to shoot? Bell let go the trigger, engaged the safety, turned the weapon around, and looked at the muzzle. It was cram-packed with mud.

Frost had jammed it into the river mud when he picked it up, deliberately tamping it into the barrel so it would blow up in Bell’s hand. Characteristic Harry Frost. Like the bent horseshoes thrown through victims’ windows to terrorize them, the chief investigator’s maimed hand would warn every Van Dorn detective: Don’t mess with Harry Frost.

Bell dunked the gun in the water and slammed it back and forth, sluicing out the mud. With any luck, it would fire a shot or two. But when he looked for his target, Harry Frost had melted into the shadows. Bell called, “Frost!” All he heard in response was laughter echoing under a distant pier.

“WHERE IS JOSEPHINE?” Isaac Bell shouted into the stockyard office telephone.

“Are you O.K., Isaac?” asked Joseph Van Dorn.

“Where is Josephine?”

“Camped out on Bedloe’s Island, fixing her flying machine. Where are you?”

“Who’s watching her?”

“Six of my best detectives and twenty-seven newspaper reporters. Not to mention Mr. Preston Whiteway, circling on a steam yacht, beaming searchlights for your fiancée to shoot moving pictures by. Are you O.K.?”

“Tip-top, soon as I get a propeller, a new wing stay, and a Remington autoload.”

“I’ll send word to Marion you’re O.K. Where are you, Isaac?”

“Weehawken stockyards. Frost got away.”

“Seems to be making a habit of that,” the boss observed coolly. “Did you wing him at least?”

“I took off one of his ears.”

“That’s a start.”

“But it didn’t stop him.”

“Where’s he headed?”

“I don’t know,” Bell admitted. His head ached, and his jaw felt like he’d been chewing thornbushes.

“Do you think he’ll try again?”

“He assured me he will not stop trying until he kills her.”

“You spoke?” The tone of Van Dorn’s voice suggested that if Bell could somehow see through telephone wire, he would be facing sharply raised eyebrows.

“Briefly.”

“What’s his state of mind?”

Isaac Bell had thought of little else since he swam ashore.

“Harry Frost is not insane,” he said. “In fact, in a strange way he’s enjoying himself. As I warned Whiteway in San Francisco, Frost knows he’s been dealt his last hand. He’s not going to fold his cards until he sets the casino on fire.”

Joseph Van Dorn said, “Nonetheless, the lengths he’s going to to avenge his wife’s supposed seduction would fit most folks’ definition of insane.”

“Let me ask you something, Joe. Why do you suppose Frost didn’t kill Josephine when they were still together?”

“What do you mean?”

“Why did Frost shoot Marco instead?”

“Put an end to the affair, hoping she’d come back.”

“Yes. Except for one thing. Having killed Marco – assuming he is dead-”

“He is,” Van Dorn interrupted. “We’ve been down that road.”

“Having killed, or tried to kill, Marco,” Bell replied evenly, “why is Frost now trying to kill Josephine?”

“He either is insane or just plain old-fashioned crazed with jealousy. The man was known for his temper.”

“Why didn’t he kill Josephine first?”

“You’re asking me to explain the order of a madman’s killings?”

“Do you know what he said to me?”

“I wasn’t there when he escaped, Isaac,” Van Dorn said pointedly.

Isaac Bell was too involved in his line of inquiry to countenance Van Dorn’s jibe. “Harry Frost said to me, ‘You don’t know what they were up to.’”

“Up to? Marco and Josephine were running off together, that’s what they were up to – or so Frost suspected.”

“No. He didn’t sound like he meant only a love affair. He indicated they were scheming. It was as if he had discovered that they had perpetuated some sort of betrayal worse than seduction.”