By the time the echo from the first knock on his door rebounded off the back of his cabin, Captain Charles Urquhart was fully awake. A lifetime at sea had given him the reflexes of a cat. By the second knock he knew through the vibrations transmitted by his mattress that the ship’s engines had been shut down, but the hiss of water flowing along her steel hull told him the Mohican had not yet begun to slow. Dishwater-colored light leaked around the curtain pulled over the room’s single porthole. With the ship heading north and his cabin on the starboard side, Urquhart estimated it was coming up on nine in the evening.

He’d been asleep less than a half hour, following a grueling twenty hours on duty as the cargo vessel ran through the tail end of an early-season hurricane.

“Come,” he called and swung his legs off his cot. The deck was covered with a carpet of such thin pile that he could feel the cool of the metal plates beneath it.

The cabin door creaked open, light from a gas lantern marking a wedge across the threshold. The ship had an electrical generator, but the few lights it powered were reserved for the bridge. “Sorry to bother, sir,” said the third officer, a Welshman named Jones.

“What is it?” Urquhart asked, the last vestiges of sleep sloughing off. No one woke the captain unless it was an emergency, and he knew he had to be ready for anything.

The man hesitated for a second, then said, “We’re not sure. We need you on the bridge.” He paused again. “Sir.”

Urquhart tossed aside his bedcovers. He thrust his feet into a pair of rubber boots and threw a ratty robe over his shoulders. A Greek fisherman’s cap finished his ridiculous outfit. “Let’s go.”

The bridge was one deck above his cabin. A helmsman stood mutely behind the large oaken wheel, his gaze not over the bow as it should have been but fixated out the port door leading to the ship’s stubby bridge wing. Urquhart followed the gaze, and although his expression didn’t change, his mind whirled.

About two miles away, an eerie blue glow clung to the horizon and blotted out the dying rays of the setting sun. It wasn’t the color of lightning or St. Elmo’s fire, which had been the captain’s first suspicion. It was a deeper blue, and a color he had never seen before.

Then all at once it expanded. Not like a fog boiling up from the ocean’s surface but like the beat of a gigantic heart. Suddenly they were inside the luminous effect, and it was as if color had texture. Urquhart could somehow feel the glow on his skin as the hairs on his arms raised up and the thick pelt of man fur that covered his torso and back prickled as if the legs of a thousand insects were crawling on his body.

“Captain,” the second mate called plaintively. He was pointing at the big compass ball mounted above the main bridge windows. Inside its liquid gimbal, the compass spun like a child’s toy top.

Like any good seaman, Charles Urquhart lived by routine, and when routine was broken, it was to be reported in the ship’s log. His next glance was to the chronograph, hanging on the back wall above a chart table, so he could record the time of this strange phenomenon. To his dismay, the two hands pointed straight down.

Not like it was six thirty, where the shorter hour hand would rest halfway to the Roman numeral seven, but straight down.

He crossed to it to check the mechanism and accidently dislodged its metal winding key. As if snatched by a force greater than gravity, the key dropped to the deck like it had been hurled at great speed. The key didn’t bounce but seemed to adhere itself to the metal deck. He stooped to retrieve it but couldn’t even wedge a fingernail between the key and the deck.

He again looked to the west, but the cobalt light cut visibility to just a few dozen yards. He did notice that the sea around the ship was so still, it appeared solid, as though it had frozen as smooth as a skating rink, only it remained as black as anthracite coal.

A few crewmen down on the main deck spotted Urquhart’s silhouette in the bridge wing door. One cupped a hand to his mouth and called, “What’s all this, Captain?”

The voice reached him like the man had yelled from the bottom of a well.

Other men appeared, and Urquhart could sense their nervous apprehension. He knew sailors were a superstitious lot. Each one of them carried talismans of various kinds, miniature dream catchers, rabbits’ feet, and lucky marbles. He’d once served with a fellow who kept a small jar of alcohol in his pocket with the preserved remains of his severed pinkie finger. He claimed losing the digit proved it was lucky. Urquhart had never pressed for the details of exactly why that was.

In order to get their minds off the strangeness of the situation, he pointed to some loose chains left haphazardly on the Mohican’s forward hatch cover.

“Stow that chain properly,” Urquhart said in his most commanding voice, “or there’ll be hell to pay.”

The four men moved from the rail at double speed, as eager to have something to do as the veteran ship’s master had suspected. But like his experience with the key, the brawny seamen could not move so much as a link of the chain. Had someone welded the entire mass of rusted steel to the hatch, he couldn’t have done a better job of adhering the chain to the ship.

It was just occurring to Urquhart that his ship had turned into a giant magnet when he heard the scream, an unworldly peal of anguish that keened higher and higher without letup.

The noise galvanized him because he recognized the voice despite the agony tearing through it, and he knew what was happening to the man.

The chief engineer, a Scotsman, had his cabin down the hallway from Urquhart’s own. Urquhart reached McTaggert’s door and burst through it only seconds after hearing him scream.

In the beam of the brass hurricane lantern Urquhart’d snatched from the second mate, he saw the shirtless Scot atop his bed with a look of terror etched upon his face. He was pawing at his chest, or, more precisely, at the big scar that bisected his left pectoral muscle. The scar was a souvenir of a boiler explosion some twenty years back, and behind it, as McTaggert liked to brag, was a piece of pot metal the ship’s cook who’d stitched him up at the time had been unable to remove.

“Flip over, Conner,” Urquhart shouted, but knew he was too late.

A fresh scream exploded from the engineer, a sound so sharp and so full of pain that Urquhart winced. And then a sputter of blood bubbled from Conner McTaggert’s lips. The two men’s eyes locked, and a silent message passed between them. Good-bye, it said.

The sputter turned into a continuous gout of rich arterial blood as the shard of metal lodged in his chest tore through his heart and lungs as it was drawn inexorably deckward by the powerful magnetic forces at play. The pain that had transformed his face into an ugly mask had passed, and the crimson stain running from chin to chest was the only testament to the man’s last horrifying seconds.

A moment later came a wet sucking sound, then the metallic ting of the chunk of shrapnel hitting the deck after passing all the way through McTaggert’s body.

Urquhart closed the cabin door before any of the other crew members saw the corpse. He returned to the bridge, his face ashen and his hands a little unsteady. The glow still spread over the ship with its eerie light, while the men on deck had given up their task of stowing the chain and peered anxiously toward where the glow had first emanated.

The sea remained glassy, and not a breath of air stirred the ship’s rigging. The plume of smoke from her still-fired boilers shot straight into the sky and hung over the Mohican like a pall.