on one side, stained and gouged on the other where boards had once been nailed. A coil of rope lay beside the axes.

High in the upper branches, Blackie braced himself with negligent confidence and stared along the concrete ribbon.

From here, he thought, you'd almost think the place was still alive, instead of crumbling around our ears.

The windows of the distant houses were dark, unglassed holes, but the sunlight made the masonry clean and shining. To Blackie, the ragged tops of most of the buildings were as natural as the tattered look of the few people he knew. Beyond, toward the center of the city, was real evidence of his race's bygone might—a vast jumble of shattered stone and fused metal. Queer weeds and mosses infected the area, but it would be centuries before they could mask the desolation.

Better covered, were the heaps along the road, seemingly shoved just beyond the gravel shoulders—mouldering mounds which legend said were once machines to ride in along the pavement.

Something glinted at the bend of the highway. Blackie peered closer.

He swarmed down the tree from branch to branch, so lithely that the trio below hardly had the warning of the vibrating leaves before he dropped, cat-footed, among them.

"They're comin'!"

He shrugged quickly into his stained jacket, emulated in silent haste by the others. Vito rubbed his hands down the hairy chest left revealed by his open jacket and hefted one of the clubs. In his broad paws, it seemed light.

They were quiet, watching Sid peer out through narrowly parted brush of the undergrowth. Blackie fidgeted behind him. Finally, he reached out as if to pull the other aside, but at that moment Sid released the bushes and crouched.

The others, catching his warning glance, fell prone, peering through shrubbery and around tree trunks with savage eyes.

The distant squawk of a jay became suddenly very clear, as did the sighing of a faint breeze through the leaves overhead. Then a new, clanking, humming sound intruded.

A procession of three vehicles rolled along the highway at an unvarying pace which took no account of patches or worn spots. They jounced in turn across a patch laid over a previous, unsuccessful patch, and halted before the felled tree. Two were bulldozers; the third was a light truck with compartments for tools. No human figures were visible.

A moment later, the working force appeared—a column of eight robots. These deployed as they reached the obstacle, and explored like colossal ants along its length.

"What're they after?" asked Mike, whispering although he lay fifty yards away.

"They're lookin' over the job for whatever sends them out," Blackie whispered back. "See those little lights stickin' out the tops o' their heads? I heard tell, once, that's how they're run."

Some of the robots took saws from the truck and began to cut through the tree trunk. Others produced cables and huge hooks to attach the obstacle to the bulldozers.

"Look at 'em go!" sighed Sid, hunching his stiff shoulders jealously. "Took us hours, an' they're half done already."

They watched as the robots precisely severed the part of the tree that blocked the highway, going not one inch beyond the gravel shoulder, and helped the bulldozers to tug it aside. On the opposite side of the concrete, the shoulder tapered off into a six-foot drop. The log was jockeyed around parallel to this ditch and rolled into it, amid a thrashing of branches and a spurting of small pebbles.

"Glad we're on the high side," whispered Mike. "That thing 'ud squash a guy's guts right out!"

"Keep listenin' to me," Blackie said, "an' you'll keep on bein' in the right place at the right time."

Mike raised his eyebrows at Vito, who thrust out his lower lip and nodded sagely. Sid grinned, but no one contradicted the boast.

"They're linin' up," Blackie warned tensely. "You guys ready? Where's that rope?"

Someone thrust it into his hands. Still