The jagged fragments of masonry Brett had knocked from the wall lay as he had left them. He stepped through the opening, peered down into the murky pit, trying to judge its depth. A hundred feet at least. Perhaps a hundred and fifty.

He unslung the rope from his shoulder, tied one end to the bra.s.s stump, threw the coil down the precipitous side. It fell away into darkness, hung swaying. It was impossible to tell whether the end reached any solid footing below. He couldn"t waste any more time looking for help.

He would have to try it alone.

There was a sc.r.a.pe of shoe leather on the pavement outside. He turned, stepped out into the white sunlight. The fat man rounded the corner, recoiled as he saw Brett. He flung out a pudgy forefinger, his protruding eyes wide in his blotchy red face.

"There he is! I told you he came this way!" Two uniformed policemen came into view. One eyed the gun at Brett"s side, put a hand on his own.

"Better take that off, sir."

"Look!" Brett said to the fat man. He stooped, picked up a crust of masonry. "Look at this--just a sh.e.l.l--"

"He"s blasted a hole right in that building, officer!" the fat man shrilled. "He"s dangerous."

The cop ignored the gaping hole in the wall. "You"ll have to come along with me, sir. This gentleman registered a complaint ..."

Brett stood staring into the cop"s eyes. They were pale blue eyes, looking steadily back at him from a bland face. Could the cop be real?

Or would he be able to push him over, as he had other golems?

"The fellow"s not right in the head," the fat man was saying to the cop.

"You should have heard his crazy talk. A troublemaker. His kind have got to be locked up!"

The cop nodded. "Can"t have anyone causing trouble."

"Only a young fellow," said the fat man. He mopped at his forehead with a large handkerchief. "Tragic. But I"m sure that you men know how to handle him."

"Better give me the gun, sir." The cop held out a hand. Brett moved suddenly, rammed stiff fingers into the cop"s ribs. He stiffened, toppled, lay rigid, staring up at nothing.

"You ... you killed him," the fat man gasped, backing. The second cop tugged at his gun. Brett leaped at him, sent him down with a blow to the ribs. He turned to face the fat man.

"I didn"t kill them! I just turned them off. They"re not real, they"re just golems."

"A killer! And right in the city, in broad daylight."

"You"ve got to help me!" Brett cried. "This whole scene: don"t you see?

It has the air of something improvised in a hurry, to deal with the unexpected factor; that"s me. The Gels know something"s wrong, but they can"t quite figure out what. When you called the cops the Gels obliged--"

Startlingly the fat man burst into tears. He fell to his knees.

"Don"t kill me ... oh, don"t kill me ..."

"n.o.body"s going to kill you, you fool!" Brett snapped. "Look! I want to show you!" He seized the fat man"s lapel, dragged him to his feet and across the sidewalk, through the opening. The fat man stopped dead, stumbled back--

"What"s this? What kind of place is this?" He scrambled for the opening.

"It"s what I"ve been trying to tell you. This city you live in--it"s a hollow sh.e.l.l. There"s nothing inside. None of it"s real. Only you ...

and me. There was another man: Dhuva. I was in a cafe with him. A Gel came. He tried to run. It caught him. Now he"s ... down there."

"I"m not alone," the fat man babbled. "I have my friends, my clubs, my business a.s.sociates. I"m insured. Lately I"ve been thinking a lot about Jesus--"

He broke off, whirled, and jumped for the doorway. Brett leaped after him, caught his coat. It ripped. The fat man stumbled over one of the cop-golems, went to hands and knees. Brett stood over him.

"Get up, d.a.m.n it!" he snapped. "I need help and you"re going to help me!" He hauled the fat man to his feet. "All you have to do is stand by the rope. Dhuva may be unconscious when I find him. You"ll have to help me haul him up. If anybody comes along, any Gels, I mean--give me a signal. A whistle ... like this--" Brett demonstrated. "And if I get in trouble, do what you can. Here ..." Brett started to offer the fat man the gun, then handed him the hunting knife. "If anybody interferes, this may not do any good, but it"s something. I"m going down now."

The fat man watched as Brett gripped the rope, let himself over the edge. Brett looked up at the glistening face, the damp strands of hair across the freckled scalp. Brett had no a.s.surance that the man would stay at his post, but he had done what he could.

"Remember," said Brett. "It"s a real man they"ve got, like you and me ... not a golem. We owe it to him." The fat man"s hands trembled. He watched Brett, licked his lips. Brett started down.

The descent was easy. The rough face of the excavation gave footholds.

The end of a decaying timber projected; below it was the stump of a crumbling concrete pipe two feet in diameter. Brett was ten feet below the rim of floor now. Above, the broad figure of the fat man was visible in silhouette against the jagged opening in the wall.

Now the cliff shelved back; the rope hung free. Brett eased past the cut end of a rusted water pipe, went down hand over hand. If there were nothing at the bottom to give him footing, it would be a long climb back ...

Twenty feet below he could see the still black water, pockmarked with expanding rings where bits of debris dislodged by his pa.s.sage peppered the surface.

There was a rhythmic vibration in the rope. Brett felt it through his hands, a fine sawing sensation ...

He was falling, gripping the limp rope ...

He slammed on his back in three feet of oily water. The coils of rope collapsed around him with a sustained splashing. He got to his feet, groped for the end of the rope. The glossy nylon strands had been cleanly cut.

For half an hour Brett waded in waist-deep water along a wall of damp clay that rose sheer above him. Far above, bars of dim sunlight crossed the upper reaches of the cavern. He had seen no sign of Dhuva ... or the Gels.

He encountered a sodden timber that projected above the surface of the pool, clung to it to rest. Bits of flotsam--a plastic pistol, bridge tallies, a golf bag--floated in the black water. A tunnel extended through the clay wall ahead; beyond, Brett could see a second great cavern rising. He pictured the city, silent and empty above, and the honey-combed earth beneath. He moved on.

An hour later Brett had traversed the second cavern. Now he clung to an outthrust spur of granite directly beneath the point at which Dhuva had disappeared. Far above he could see the green-clad waitress standing stiffly on her ledge. He was tired. Walking in water, his feet floundering in soft mud, was exhausting. He was no closer to escape, or to finding Dhuva, than he had been when the fat man cut the rope. He had been a fool to leave the man alone, with a knife ... but he had had no choice.

He would have to find another way out. Endlessly wading at the bottom of the pit was useless. He would have to climb. One spot was as good as another. He stepped back and scanned the wall of clay looming over him.

Twenty feet up, water dripped from the broken end of a four-inch water main. Brett uncoiled the rope from his shoulder, tied a loop in the end, whirled it and cast upward. It missed, fell back with a splash. He gathered it in, tried again. On the third try it caught. He tested it, then started up. His hands were slippery with mud and water. He twined the rope around his legs, inched higher. The slender cable was smooth as gla.s.s. He slipped back two feet, then inched upward, slipped again, painfully climbed, slipped, climbed.

After the first ten feet he found toe-holds in the muddy wall. He worked his way up, his hands aching and raw. A projecting tangle of power cable gave a secure purchase for a foot. He rested. Nearby, an opening two feet in diameter gaped in the clay: a tunnel. It might be possible to swing sideways across the face of the clay and reach the opening. It was worth a try. His stiff, clay-slimed hands would pull him no higher.

He gripped the rope, kicked off sideways, hooked a foot in the tunnel mouth, half jumped, half fell into the mouth of the tunnel. He clung to the rope, shook it loose from the pipe above, coiled it and looped it over his shoulder. On hands and knees he started into the narrow pa.s.sage.

The tunnel curved left, then right, dipped, then angled up. Brett crawled steadily, the smooth stiff clay yielding and cold against his hands and sodden knees. Another smaller tunnel joined from the left.

Another angled in from above. The tunnel widened to three feet, then four. Brett got to his feet, walked in a crouch. Here and there, barely visible in the near-darkness, objects lay imbedded in the mud: a silver-plated spoon, its handle bent; the rusted engine of an electric train; a portable radio, green with corrosion from burst batteries.

At a distance, Brett estimated, of a hundred yards from the pit, the tunnel opened into a vast cave, green-lit from tiny discs of frosted gla.s.s set in the ceiling far above. A row of discolored concrete piles, the foundations of the building above, protruded against the near wall, their surfaces nibbled and pitted. Between Brett and the concrete columns the floor was littered with pale sticks and stones, gleaming dully in the gloom.

Brett started across the floor. One of the sticks snapped underfoot. He kicked a melon-sized stone. It rolled lightly, came to rest with hollow eyes staring toward him. A human skull.