Harbor cops hunting coal pirates had noticed Uncle Donny and his two friends following a coal barge in an oyster scow. Uncle Donny had declined to let the police board it for inspection. Pistol shots were exchanged. The cops had boarded anyway. Uncle Donny and his friends had jumped into the Kill and swam for shore.

Darbee’s friends were caught, but the old man swam for a car float that he had been eyeing for several days because the barge was tied up all by itself, unattended, and was carrying a pair of freight cars that might contain cargo. Tiring in the cold water as he hid in the shadow of the overhanging prow, the old man had begun to sink only to step on something solid where it was too deep to stand. When the cops gave up, Jimmy and Marv, who had been watching from the Staten Island side, had rescued their Dutch uncle in another oyster boat. Then they took a closer look at the barge. Under it, they saw the outline of a submarine.

“Bigger than the Navy Holland. Same boat, but it looks like they added on a chunk at each end.”

“Uncle Donny knows the Holland,” Jimmy Richards explained. “He took us off Brooklyn to watch the Navy tests. When was that?”

“In 1903. She made fifteen knots with her conning turret out of the water. And six submerged.”

Bell reached for the telephone. “So you have good reason to believe that you saw a submarine.”

“Want to come see it?” asked Marv Gordon.

“Yes.”

“Told you he would,” said Uncle Donny.

Isaac Bell telephoned the New York Police Harbor Squad, rounded up Archie Abbott and Harry Warren, and grabbed a golf bag. The Ninth Avenue Elevated express whisked the Van Dorns and the scowmen to the Battery at the southern tip of Manhattan in ten minutes. A forty-foot Harbor Squad launch had its steam up at Pier A.

“Don’t touch anything,” the captain warned the Staten Islanders as they trooped warily aboard. He did not want to tow Donald Darbee’s scow, which was moored nearby, but Bell insisted and slipped him twenty dollars “for your crew.”

“Never thought I’d be on one of these,” muttered old Darbee as they churned away from the pier.

A water cop muttered back, “Except in handcuffs.”

Bell said to Archie and Harry, “If there’s no submarine in the Kill Van Kull, we’re going to end up in a cross fire.”

“You really think we’re going to find one, Isaac?”

“I believe they think they saw a submarine. And a submarine would make those torpedoes a much deadlier affair than a surface torpedo boat. Nonetheless, I will believe a submarine when I see one.”

The Harbor Squad launch plowed across the Upper Bay, threading a swift course through ferries, tugs, barges, and oceangoing schooners and steamers. A thunderous whistle announced the New York arrival of an Atlantic liner passing through the Verrazano Narrows. Tugboats meeting her piped replies. A steady stream of car floats carried freight trains between New Jersey, Manhattan, Brooklyn, and the East River.

The police boat steered into the crooked channel of water between Staten Island and New Jersey known as the Kill Van Kull. Bell estimated it was a thousand feet wide, about the same as the narrow arm of the Carquinez Strait where he had captured Louis Loh swimming from Mare Island. To his left rose the hills of Staten Island. The city of Bayonne spread to his right. Docks, warehouses, boatyards, and residences lined the banks. Four miles down the waterway, Richards and Gordon said, “There she is!”

The car float stood by itself, tied to the shore beside the flat green back lawn of a large frame house in a district of similar dwellings. It was an old New Jersey Central barge of the three-track type, short and wide, with a boxcar on the nearside tracks and a tall gondola on the inside. The middle track appeared to be empty, though the men on the police launch could not see the space between the two cars.

“What submarine?” asked the Harbor Squad captain.

“Under it,” growled Donald Darbee. “They cut a well in the middle of the barge for the conning turret.”

“You saw that?”

“No. But how else could they get in and out?”

The launch captain glowered at Isaac Bell. “Mr. Bell, I predict that my boss is going to be talking to your boss, and neither of us is going to be very happy about it.”

“Let’s get closer,” said Bell.

“There isn’t enough water there for a Holland submarine.”

“It’s plenty deep,” Donald Darbee retorted quietly. “The tide scours the bank on this side.”

The helmsman called for Dead Slow, and drew within fifty feet.

The Van Dorns, the scowmen, and the harbor police peered into the murky water. The launch drifted closer to the car float.

“Lot of mud stirred up,” Darbee muttered worriedly.

“Our propeller’s stirring it,” said the captain. “Told you it’s too shallow.” To the helmsman he barked, “Back off before we run aground.”

Darbee said, “There’s thirty feet of water here if there’s an inch.” “Then what’s causing that mud?”

“That’s what I’m wondering.”

“So am I,” said Isaac Bell, peering into the water. Bubbles were rising from the murk and hissing on the surface.

BACK AWAY!” ISAAC BELL SHOUTED. “BACK! FULL ASTERN.”

The helmsman and the engineer had quick reflexes. They reversed the engine in an instant. The propeller churned backward. Smoke and steam shot from the short stack. The boat stopped. But before it could gather way in reverse, a gray malevolent form rose swiftly under it.

“Grab ahold!”

Bell saw a pipe emerge just ahead of the launch-the periscope, a tube of angled mirrors, the submarine’s eye. A squat round turret broke the surface, the conning tower, rimmed with handrails. Then a mighty blow from underneath smashed into the bottom of the police launch and pushed its forty-foot hull out of the water. Its keel shattered with a loud crack of splitting wood, and still the police boat rose, lifted by a powerful steel hull that broke the surface like a maddened sperm whale.

The police launch fell onto its side, spilling Van Dorns, cops, and scowmen into the Kill.

Bell jumped onto the steel hull and waded through waist-deep water to the conning tower. He grabbed the handrails that surrounded the hatch on top and reached for a wheel that would open the hatch.

“Look out, Isaac!” Archie Abbott yelled. “He’s going under!”

Ignoring Archie and the water that was suddenly climbing up his chest, Bell threw his weight on the wheel. For a second, it wouldn’t budge. Then he thought he felt it move. Salt water rushed over his shoulders, his mouth, his nose, his eyes. Suddenly the submarine was surging ahead. He held the wheel as long as he could, still struggling to open it, but the force of the rushing water ripped it from his hands. The hull raced under him, and he realized, too late, that the propeller driving it was about to cut him to pieces.

He pushed off desperately with both boots and swam with all his strength. The water rushing past the hull sucked him back. He felt the hull sliding under him. Something hit him hard. It threw him aside and drove him deep. A powerful thrust of turbulence tumbled him deeper. Slammed about in the submarine’s propeller wash, he realized that he had been struck by cowling that protected the propeller and, in this instance, protected him, too, from the thrashing blades.

He fought to the surface, saw the conning turret racing up the Kill Van Kull, and swam after it. Behind him, Archie was helping Harry Warren climb onto the muddy bank, Richards and Gordon and the engineer were holding ropes dangling from the barge, and the police captain clung to his overturned launch. “Telephone for help!” the captain yelled, and two cops staggered toward the frame house.

Donald Darbee was climbing onto his oyster scow, which had broken free of the sinking launch.