But he had a destination, and he would not be deterred.

He had been an Arctic solitary for almost twenty years, driven from his harem by a younger, stronger bull. Dying, he longed for the coves of youth and to see his kind again. It was breeding season near the equator.

His ancestors had been creatures of the land. They had crawled back to the ocean before man had crept from trees. He knew that he would never mount another cow, but he longed to die in warmer waters, beached on a golden strand.

He had been traveling mostly in silence, by dead reckoning, for days, seldom daring to echolocate on remembered peaks below.

He could see the sun by daylight. But age had dimmed the vision of the eye that he had left, so he could not navigate by moonlight or the stars.

He was sure that the Gulf Stream had swept him from the steep Bermuda Rise. He decided to risk everything for a fix on the terrain below.

Blat... He snorted, and listened. Blat... blat... blat...

Ping...ping...

The immediate echo startled him. Instantly he switched to a racheting mode, which would have sounded to man like a distant outboard motor. But to him it defined, in the pitch-black water, a perfect picture of a great white shark, rising toward him from the depths.

He flung up his flukes and dived, his back shimmering in the starlight like an island engulfed by tides.

As he sounded, trailing clouds of phosphorescence, the great white struck. It snatched off a tiny pectoral fin, a vestige of land legs, and destroyed the whale's stability. The sperm spiraled helplessly for a moment, unable to get his bearings. He felt the shark boring in on his blind side and began to flail his flukes.

But now, in a flash of searing pain, he realized that the creature was fastened to his side, burdening him. The sperm bellowed angrily, for in more agile days he might have shaken him loose and slammed out his life with one enormous swipe.

The shark hung on, but the whale would not give up. He had fought a dozen males as large as himself and won all the fights but the last. In agony, he rose to the surface and broached like a dolphin, carrying the shark with him high above the waves. At the crest of his leap he turned and fell, slamming his fifty-ton body on the writhing, tearing shark.

The blow dislodged the great white shark and stunned him. He swam away.

For a moment the sperm whale rested, rocking in waves of pain. He blew, spouting a bloody fountain fifty feet high, with a sigh that could be heard for half a mile.

The shark circled, shaking his head. The smell of blood, heavy in the water, drew him back, and he bored in on the same gushing wound.