He swept on tirelessly, never sleeping, for to slumber was to plunge into the abyss. He had no reason to descend, for in the depths was no worthy food but giant squid, and there was easier prey at the levels where he swam.

Six hundred miles west of Cape Fear, South Carolina, he became aware of an explosive blat... blat... blat.... It came from somewhere to the east, in the direction of the Mares Deep.

His instincts told him that a sperm whale—a large bull, from the sound of it—was echolocating, to navigate or for prey.

Sperm were creatures of sunlight when they cruised, but of darkness when they dived. They found their breath where the wind swept free, and their food where the great white seldom swam, a thousand feet below the surface of the sea.

The shark had no interest in a live and active adult sperm. Great whites depended on the shock of their initial headlong rush to stun their prey. They did not like a battle afterward, and sperm whales fought savagely, to the death.

Men had called the great sperm "emperors," for their size, dignity, and violence when provoked. The rush of an angry bull whale—fifty or sixty feet long, weighing fifty tons, and fighting for his life—could crush the white. And the whale's great teeth—eight inches long—could impale the biggest shark.

But this sperm seemed different. He was sending out a hunting blast, echolocating for squid or navigating off echoes from the ridges a mile below, but the sound somehow lacked timbre. The shark sensed weakness.

The bull was sick or wounded. If so, he was fair game. Synapses were triggered in the great white's tiny brain, and he speeded the rhythm of his tail. He began the long, long quest to see where the sperm whale was.

***

The old sperm whale swam doggedly southward on the surface, ramming through the Gulf Stream chop. He had only one eye, his left. From the other protruded the broken half of a harpoon. It had slammed home out of nowhere, propelled by a South African pirate whaler's gun while he slumbered near an iceberg off Newfoundland a week before.

The harpoon, if it had penetrated another foot, would have destroyed the largest brain the world had ever known, seven times the size of man's.

Instead it had lodged within the eyeball, sending waves of agony through the wallowing body at every stroke of his sixteen-foot flukes. Another harpoon, unbroken, rose from his dorsal hump. This one caused no pain except when a Gulf Stream breaker slammed his back.

Knowing that he was unfit for another battle with man—whom, he suspected, homed on his hunting peal—or with his cousins, the killer whales, or even with a shark, he had held silence for most of the last two thousand miles. He would never again take a squid, he knew, and would starve if his wounds did not kill him.