There was a killer loose on the range. A 'copter patrol, five hundred miles off Greenland, had seen the great corpse staining the sea crimson as it wallowed in the waves. Within seconds, the intricate warning system had been alerted : men were plotting circles and moving counters on the North Atlantic chart—and Don Burley was still rubbing the sleep from his eyes as he dropped silently down to the twenty-fathom line.
The pattern of green lights on the tell-tale was a glowing symbol of security. As long as that pattern was unchanged, as long as none of those emerald stars winked to red, all was well with Don and his tiny craft. Air—fuel—power—this was the triumvirate which ruled his life. If any of them failed, he would be sinking in a steel coffin down toward the pelagic ooze, as Johnnie Tyndall had done the season before last. But there was no reason why they should fail; the accidents one foresaw, Don told himself reassuringly, were never the ones that happened.
He leaned across the tiny control board and spoke into the mike. Sub 5 was still close enough to the mother ship for radio to work, but before long he'd have to switch to the sonics.
"Setting course 255, speed 50 knots, depth 20 fathoms, full sonar coverage. . . . Estimated time to target area, 70 minutes.... Will report at 10-minute intervals. That is all.... Out."
The acknowledgement, already weakening with range, came back at once from the Herman Melville.
"Message received and understood. Good hunting. What about the hounds?"
Don chewed his lower lip thoughtfully. This might be a job he'd have to handle alone. He had no idea, to within fifty miles either way, where Benj and Susan were at the moment. They'd certainly follow if he signaled for them, but they couldn't maintain his speed and would soon have to drop behind. Besides, he might be heading for a pack of killers, and the last thing he wanted to do was to lead his carefully trained porpoises into trouble. That was common sense and good business. He was also very fond of Susan and Benj.
"It's too far, and I don't know what I'm running into," he replied. "If they're in the interception area when I get there, I may whistle them up."
The acknowledgement from the mother ship was barely audible, and Don switched off the set. It was time to look around.
He dimmed the cabin lights so that he could see the scanner screen more clearly, pulled the polaroid glasses down over his eyes, and peered into the depths. This was the moment when Don felt like a god, able to hold within his hands a circle of the Atlantic twenty miles across, and to sec clearly down to the still-unexplored deeps, three thousand fathoms below. The slowly rotating beam of inaudible sound was searching the world in which he floated, seeking out friend and foe in the eternal darkness where light could never penetrate. The pattern of soundless shrieks, too shrill even for the hearing of tile bats who had invented sonar a million years before man, pulsed out into the watery night: the faint echoes came tingling back as floating, blue-green flecks on the screen.
Through long practice, Don could read the message with effortless ease. A thousand feet below, stretching out to his submerged horizon, was the scattering layer—the blanket of life that covered half the world. The sunken meadow of the sea, it rose and fell with the passage of the sun, hovering always at the edge of darkness. But the ultimate depths were no concern of his. The flocks he guarded, and the enemies who ravaged them, belonged to the upper levels of the sea.
Don flicked the switch of the depth-selector, and his sonar beam concentrated itself into the horizontal plane. The glimmering echoes from the abyss vanished, but he could see more clearly what lay around him here in the ocean's stratospheric heights. That glowing cloud two miles ahead was a school of fish; he wondered if Base knew about it, and made an entry in his log. There were some larger, isolated blips at the edge of the school—the carnivores pursuing the cattle, insuring that the endlessly turning wheel of life and death would never lose momentum. But this conflict was no affair of Don's; he was after bigger game.
Sub 5 drove on toward the west, a steel needle swifter and more deadly than any other creature that roamed the seas. The tiny cabin, lit only by the flicker of lights from the instrument board, pulsed with power as the spinning turbines thrust the water aside. Don glanced at the chart and wondered how the enemy had broken through this time. There were still many weak points, for fencing the oceans of the world had been a gigantic task. The tenuous electric fields, fanning out between generators many miles apart, could not always hold at bay the starving monsters of the deep. They were learning, too. When the fences were opened, they would sometimes slip through with the whales and wreak havoc before they were discovered.
The long-range receiver bleeped plaintively, and Don switched over to TRANSCRIBE. It wasn't practical to send speech any distance over an ultrasonic beam, and code had come back into its own. Don had never learned to read it by ear, but the ribbon of paper emerging from the slot saved him the trouble.
COPTER REPORTS SCHOOL 50-100 WHALES HEADING 95 DEGREES GRID REF X186475 Y438034 STOP. MOVING AT SPEED. STOP. MELVILLE. OUT.
Don started to set the coordinates on the plotting grid, then saw that it was no longer necessary. At the extreme edge of his screen, a flotilla of faint stars had appeared. He altered course slightly, and drove head-on toward the approaching herd.
The 'copter was right: they were moving fast. Don felt a mounting excitement, for this could mean that they were on the run and luring the killers toward him. At the rate at which they were traveling he would be among them in five minutes. He cut the motors and felt the backward tug of water bringing him swiftly to rest.
Don Burley, a knight in armor, sat in his tiny dim-lit room fifty feet below the bright Atlantic waves, testing his weapons for the conflict that lay ahead. In these moments of poised suspense, before action began, his racing brain often explored such fantasies. He felt a kinship with all shepherds who had guarded their flocks back to the dawn of time. He was David, among ancient Palestinian hills, alert for the mountain lions that would prey upon his father's sheep. But far nearer in time, and far closer in spirit, were the men who had marshaled the great herds of cattle on the American plains, only a few lifetimes ago. They would have understood his work, though his implements would have been magic to them. The pattern was the same; only the scale had altered. It made no fundamental difference that the beasts Don herded weighed almost a hundred tons, and browsed on the endless savannahs of the sea.
The school was now less than two miles away, and Don checked his scanner's continuous circling to concentrate on the sector ahead. The picture on the screen altered to a fanshaped wedge as the sonar beam started to flick from side to side; now he could count every whale in the school, and even make a good estimate of its size. With a practiced eye, he began to look for stragglers.
Don could never have explained what drew him at once toward those four echoes at the southern fringe of the school. It was true that they were a little apart from the rest, but others had fallen as far behind. There is some sixth sense that a man acquires when he has stared long enough into a sonar screen—some hunch which enables him to extract more from the moving flecks than he has any right to do. Without conscious thought, Don reached for the control which would start the turbines whirling into life. Sub 5 was just getting under way when three leaden thuds reverberated through the hull, as if some-one was knocking on the front door and wanted to come in.