He carried such a scrap in his hand and studied it now and again. He saw it to be some sort of tough, light alloy, once he had scraped and rubbed the dirt from it, uncor-rupted after all these years. What were the forces that had formed it? What heats? What pressures? It told him that something peculiar had once existed nearby.

That evening he walked through the still standing shell of a large building. He could not even guess what might once have been transacted within it. But twice he thought that he heard scurrying sounds near at hand as he explored. He decided to camp at some distance from the ruin.

He could not decide whether a fire would attract or repel anything that might dwell nearby. Finally, the lack of sufficient kindling materials to keep a blaze going for very long persuaded him to do entirely without. He ate dry rations and rolled himself into his blanket on a ledge eight feet above the ground. He placed his blade within easy reach.

How long he had slept, he could not say. Several hours, it felt, when he was awakened by a scratching noise. He was alert in an instant, hand moving toward the weapon. He turned his head slightly, muscles tensing, and beheld the thing which moved over the rocks below, coming in his direction.

Its dark, segmented body gleamed in the moonlight as it crept over the rocks on numerous tiny feet, its front end sometimes raised, sometimes lowered. It was three or four times his own size, and it resembled nothing so much as a gigantic, metallic caterpillar moving along the trail he had followed to this place. Mounted near the forward end was something small and twisted and vaguely man-shaped, clutching what appeared to be reins in its left hand and the shaft of a long spear in the other. The beast reared, rising as high as the ledge, swayed, then dropped to the ground once more and proceeded as if sniffing out his path.

Hackles risen, a cold lump in the pit of his stomach, Mark eyed a possible escape route among the rocks below and to the right. If he moved quickly enough there might still be a sufficient margin....

He breathed deeply, vaulted to the ground and twisted his ankle beneath him. Rising, limping, he headed toward the rocks. He heard a sharp whistling noise behind him and an increase in the scratching sounds. He dodged as best he could, thinking of the spear in the thing's hand.

He looked back once and saw that he seemed to be holding his own. The spear-arm was cocked, but the rocks were right before him now. He dove and heard the shaft clatter on stone behind him. Recovering immediately, he continued on, heading obliquely back in the direction of the ruin he had visited earlier.

The noises behind him did not diminish. Apparently, the monstrosity could move at a faster pace than that at which he had first seen it coming.

He darted among rocks, keeping the sounds to the rear and the ruin roughly ahead. There had been places to climb, places to hide there--places better suited for defense than the open ground of this rock maze.

He rounded a huge boulder, froze, and barely had time to bring his blade into play. Another of the things, also bearing a rider, appeared to have been searching or waiting for him. It was reared upright only feet away, and the spear was already descending.

He parried, driving the shaft aside, and swung a backhanded cut toward the swaying creature. It rang like a bell and dropped forward. He stepped aside, feeling a sharp pain in his right ankle, then thrust upward toward the gnarled rider. There came a scream as his blade connected and entered, somewhere. He dragged it free, turned, ran.

There were no sounds of pursuit, and when he glanced back he saw the beast, now riderless, groping aimlessly among the rocks. He began to draw a deep breath, and then the world gave way beneath him. He fell a short distance through darkness and landed shoulder-first on a hard surface. The blade fell from his hand with a clanging sound, and he immediately retrieved it. There came a sharp, slamming noise from overhead, and dust, gravel and pieces of earth fell about him. Suddenly then, there was light, but his eyes did not immediately adjust to it.

When the effects of the brightness had passed, he still did not understand what lay before him.

A table... Yes, he recognized that--and the chairs. But where was the main light source? What was that large gray thing with the glassy rectangle at its center? And all those tiny lights?

Nothing moved about him, save for the settling dust. He got to his feet, advancing slowly.

"Hello?" he whispered.

"Yes, hello, hello!" came a loud voice. "Hello?"

"Where are you?" he asked, halting and turning in a slow circle.

"Here, with you," was the reply. The words had an archaic accent to them, like that of the Northlanders.

"I do not see you. Who are you?"

"My, you speak strangely! Foreigner? I am a teaching machine, a library computer."

"My words may seem strangely accented and assembled because of the passage of time," Mark said, with a sudden insight concerning the age and function of the device. "Can you make allowances, adjust for this? I am having a difficult time understanding even your simplest statements."

"Yes. Talk a lot. I need a good sample. Tell me about yourself and the things that you wish to know."

Mark smiled and lowered his blade. He limped to the nearest chair and slumped into it. He rubbed his shoulder.

"I will," he said, moments later. "But how is this place lighted?"

The screen glowed before him. Beneath a heavy layer of dust, a wiring diagram suddenly appeared upon it.

"Is that what you mean?" asked the voice.

"Maybe. I'm not certain."

"Do you know what it is?"

"Not yet," he said, "but I intend to. If you will instruct me."

"I have the means to provide for your well-being for so long as you wish to remain here. I will instruct you."

"I think I may have just fallen into the very thing I sought," Mark replied. "I'll tell you about myself, and you tell me about power sources. ..."

Daniel Chain--a junior at State, working on his certificate in Medieval Studies; slim and hard, after two years on the boxing and fencing teams; less than happy at the subtle pressure still exerted by his father for him to change his History and Linguistics major and join him in the business--sat upon the tall stool, thinking of all these matters and others, after the fashion of half-controlled reverie which informed his mind whenever he played.

The club was dim and smoky. He had followed Betty Lewis, who sang torch songs and blues numbers accompanied by piano rolls and a deep decolletage and who always drew heavy applause when she took her bows. Now he was filling the room with guitar sounds. He played on Saturday nights and alternate Fridays, doing as many instrumentals as vocals. The people seemed to like his music both ways. Right now, he was in a nonvocal mood.

Tonight was the other Friday, and the place was considerably less than packed. He recognized several familiar faces at the small tables, some of them nodding in time with the beat.

He sculpted the swirls of smoke as they drifted up toward the lights, into castles, mountain ranges, forests and exotic beasts. The mark on his wrist throbbed slightly as this occurred, It was strange how few of the patrons ever looked up and noticed his music-shaped daydreams hovering above their heads. Or perhaps the ones who did were already high and thought it normal.

Improvising, he moved an army across a ridge. He attacked it with dragons and tore it to pieces. Troops fled in all directions. Smiling, he upped the tempo.

In time, he saw an elbow strike a mug of beer. It slowed in midair as he played, twisting upright, retaining much of the beverage. It came to a stop inches above the floor, then descended the final distance gently. By the time its owner found it there and exclaimed upon the miracle, Dan had returned to his world of open spaces and trees, mountains and clear rivers, prancing unicorns and diving griffins.