The house was a rambling two-story affair, all curves and planes between palm trees, the island sloping swiftly from its front to a beach and dock. On one side was the airfield, on another the guard barracks. To the rear, in the direction of Dalgetty's movement, the ground became rough and wild, stones and sand and saw-grass and clumps of palmettos, climbing upward for a good two miles. On every side, he could see the infinite blue sparkle of ocean. Where could he hide?

He didn't notice the slashing blades through which he raced and the dry gulping of his lungs was something dreadfully remote. But when a bullet went past one ear, he heard that and drew more speed from some unknown depth. A glance behind revealed his pursuers boiling out of the house, men in gray with the hot sunlight blinking off their guns.

He ducked around a thicket, flopped and belly-crawled over a rise of land. On the farther side he straightened again and ran up the long slope. Another slug and another. They were almost a mile behind now but their guns had a long reach. He bent low, zigzagging as he ran. The bullets kicked up spurts of sand around him.

A six-foot bluff loomed in his path, black volcanic rock shining like wet glass. He hit it at full speed. He almost walked up its face and in the instant when his momentum was gone caught a root and yanked himself to the top. Again he was out of their sight. He sprang around another hulk of stone and skidded to a halt. At his feet, a sheer cliff dropped nearly a hundred feet to a white smother of surf.

Dalgetty gulped air, working his lungs like a bellows. A long jump down, he thought dizzily. If he didn't crack his skull open on a reef he might well be clawed under by the sea. But there was no other place for him to go.

He made a swift estimate. He had run the upward two miles in a little over nine minutes, surely a record for such terrain. It would take the pursuit another ten or fifteen to reach him. But he couldn't double back without being seen and this time they'd be close enough to fill him with lead.

Okay, son, he told himself. You're going to duck now, in more than one sense.

His light waterproof clothes, tattered by the island growth, would be no hindrance down there, but he took off his sandals and stuck them in his belt pouch. Praise all gods, the physical side of his training had included water sports. He moved along the cliff edge, looking for a place to dive. The wind whined at his feet.

There—down there. No visible rocks though the surf boiled and smoked. He willed full energy back into himself, bent his knees, jack-knifed into the air.

The sea was a hammer blow against his body. He came up threshing and tumbling, gasped a mouthful of air that was half salt spray, was pulled under again. A rock scraped his ribs. He took long strokes, always upward to the blind white shimmer of light. He got to the crest of one wave and rode it in, surfing over a razorback reef.

Shallow water. Blinded by the steady rain of salt mist, deafened by the roar and crash of the sea, he groped toward shore. A narrow pebbly beach ran along the foot of the cliff. He moved along it, hunting a place to hide.

There—a sea-worn cave, some ten feet inward, with a yard or so of fairly quiet water covering its bottom. He splashed inside and lay down, exhaustion clamping a hand on him.

It was noisy. The hollow resonance of sound filled the cave like the inside of a drum but he didn't notice. He lay on the rocks and sand, his mind spiraling toward unconsciousness, and let his body make its own recovery.

Presently he regained awareness and looked about him. The cave was dim, with only a filtered greenish light to pick out black wall's and slowly swirling water. Nobody could see much below the surface—good. He studied himself. Lacerated clothes, bruised flesh and a long bleeding gash in one side. That was not good. A stain of blood on the water would give him away like a shout.

Grimacing, he pressed the edges of the wound together and willed that the bleeding stop. By the time a good enough clot was formed for him to relax his concentration the guards were scrambling down to find him. He didn't have many minutes left. Now he had to do the opposite of energizing. He had to slow metabolism down, ease his heartbeat, lower his body temperature, dull his racing brain.

He began to move his hands, swaying back and forth, muttering the autohypnotic formulas. His incantations, Tighe had called them. But they were only stylized gestures leading to conditioned reflexes deep in the medulla. Now I lay me down to sleep....

Heavy, heavy—his eyelids were drooping; the wet walls receding into a great darkness, a hand cradling his head. The noise of surf dimmed, became a rustle, the skirts of the mother he had never known, come in to bid him goodnight. Coolness stole over him like veils dropping one by one inside his head. There was winter outside and his bed was snug.

When Dalgetty heard the nearing rattle of boots—just barely through the ocean and his own drowsiness—he almost forgot what he had to do. No, yes, now he knew. Take several long, deep breaths, oxygenate the bloodstream, then fill the lungs once and slide down under the surface.

He lay there in darkness hardly conscious of the voices, dimly perceived.

"A cave here—a place for him to hide."

"Nah, I don't see nothing."

Scrunch of feet on stone. "Ouch! Stubbed my damn toe. Nah, it's a closed cave. He ain't in here."

"Hm? Look at this, then. Bloodstains on this rock, right? He's been here, at least."

"Under water?" Rifle butts probed but could not sound the inlet.

The woman's voice. "If he is hiding down below he'll have to come up for air."

"When? We gotta search this whole damn beach. Here, I'll just give the water a burst."

Casimir, sharply—"Don't be a fool. You won't even know if you hit him. Nobody can hold his breath more than three minutes."

"Yeah, that's right, Joe. How long we been in here?"

"One minute, I guess. Give him a couple more. Cripes! D'ja see how he ran? He ain't human!"

"He's killable, though. Me, I think he's just rolling around in the surf out there. This could be fish blood. A 'cuda chased another fish in here and bit it."

Casimir: "Or if his body drifted in, it's safely under. Got a cigarette?"

"Here y'are, Miss. But say, I never thought to ask. How come you come with us?"

Casimir: "I'm as good a shot as you are, buster, and I want to be sure this job's done right."

Pause.

Casimir: "Almost five minutes. If he can come up now he's a seal. Especially with his body oxygen-starved after all that running."

In the slowness of Dalgetty's brain there was a chill wonder about the woman. He had read her thought, she was FBI, but she seemed strangely eager to hunt him down.

"Okay, le's get outta here."

Casimir: "You go on. I'll wait here just in case and come up to the house pretty soon. I'm tired of following you around."

"Okay. Le's go, Joe."

It was another four minutes or so before the pain and tension in his lungs became unendurable. Dalgetty knew he would be helpless as he rose, still in his semi-hibernating state, but his body was shrieking for air. Slowly he broke the surface.

The woman gasped. Then the automatic jumped into her hand and leveled between his eyes. "All right, friend. Come on out." Her voice was very low and shook a trifle but there was grimness in it.

Dalgetty climbed onto the ledge beside her and sat with his legs dangling, hunched in the misery of returning strength. When full wakefulness was achieved he looked at her and found she had moved to the farther end of the cave.

"Don't try to jump," she said. Her eyes caught the vague light in a wide glimmer, half frightened. "I don't know what to make of you."

Dalgetty drew a long breath and sat upright, bracing himself on the cold slippery stone. "I know who you are," he said.

"Who, then?" she challenged.

"You're an FBI agent planted on Bancroft."

Her gaze narrowed, her lips compressed. "What makes you think so?"

"Never mind—you are. That gives me a certain hold on you, whatever your purposes."

The blond head nodded. "I wondered about that. That remark you made to me down in the cell suggested—well, I couldn't take chances. Especially when you showed you were something extraordinary by snapping those straps and bursting the door open. I came along with the search party in hope of finding you."

He had to admire the quick mind behind the wide smooth brow. "You damn near did—for them," he accused her.

"I couldn't do anything suspicious," she answered. "But I figured you hadn't leaped off the cliff in sheer desperation. You must have had some hiding place in mind and under water seemed the most probable. In view of what you'd already done I was pretty sure you could hold your breath abnormally long." Her smile was a little shaky. "Though I didn't think it would be inhumanly long."

"You've got brains," he said, "but how much heart?"

"What do you mean?"

"I mean, are you going to throw Dr. Tighe and me to the wolves now? Or will you help us?"

"That depends," she answered slowly. "What are you here for?"

His mouth twisted ruefully. "I'm not here on purpose at all," Dalgetty confessed. "I was just trying to get a clue to Dr. Tighe's whereabouts. They outsmarted me and brought me here. Now I have to rescue him." His eyes held hers. "Kidnapping is a Federal offense. It's your duty to help me."

"I may have higher duties," she countered. Leaning forward, tautly, "But how do you expect to do this?"

"I'm damned if I know." Dalgetty locked moodily out at the beach and the waves and the smoking spindrift. "But that gun of yours would be a big help."

She stood for a moment, scowling with thought. "If I don't come back soon they'll be out hunting for me."

"We've got to find another hiding place," he agreed. "Then they will assume I survived after all and grabbed you. They'll be scouring the whole island for us. If we haven't been located before dark they'll be spread thin enough to give us a chance."

"It makes more sense for me to go back now," she said. "Then I can be on the inside to help you."

He shook his head. "Uh-uh. Quit making like a stereoshow detective. If you leave me your gun, claiming you lost it, that's sure to bring suspicion on you the way they're excited right now. If you don't I'll still be on the outside and unarmed—and what could you do, one woman alone in that nest? Now we're two with a shooting iron between us. I think that's a better bet."

After a while, she nodded. "Okay, you win. Assuming"—the half-lowered gun was raised again with a jerking motion—"that I will aid you. Who are you? What are you, Dalgetty?"

He shrugged. "Let's say I'm Dr. Tighe's assistant and have some unusual powers. You know the Institute well enough to realize this isn't just a feud between two gangster groups."

"I wonder...." Suddenly she clanked the automatic back into its holster. "All right. For the time being only though!"

Relief was a wave rushing through him. "Thank you," he whispered. Then, "Where can we go?"

"I've been swimming around here in the quieter spots," she said. "I know a place. Wait here."

She stepped across the cave and peered out its mouth. Someone must have hailed her, for she waved back. She stood leaning against the rock and Dalgetty saw how the sea-spray gleamed in her hair. After a long five minutes she turned to him again.

"All right," she said. "The last one just went up the path. Let's go." They walked along the beach. It trembled underfoot with the rage of the sea. There was a grinding under the snort and roar of surf as if the world's teeth ate rock.

The beach curved inward, forming a small bay sheltered by outlying skerries. A narrow path ran upward from it but it was toward the sea that the woman gestured. "Out there," she said. "Follow me." She took off her shoes as he had done and checked her holster: the gun was waterproof, but it wouldn't do to have it fall out. She waded into the sea and struck out with a powerful crawl.