"Who gave you your order?" Retief asked.

"Our masters," replied a voice like a sand-filled gearbox.

"That was a long time ago," Retief said. "Matters have changed somewhat-"

"Yes, indeed," Magnan chimed in. "You see, now that your old masters are all dead, we're taking over their duties-"

"Our duties are to see you dead," Red-eye boomed, raising a pair of yard-long cleavers.

"Help!" Magnan yelped.

"We wouldn't want to stand in the way of duty," Retief said, watching the poised cutting edges, "but suppose we turned out to be your masters, after all? I'm sure you wouldn't want to make the mistake of slicing up your legitimate owners."

"You see, we took over where they left off," Magnan said hastily. "We're, ah, looking after all their affairs for them, carrying out their wishes as we understand them, tidying up-"

"There is no mistake, Terran. You are not our masters."

"You said masters are better than robots," Retief reminded the machine. "If we can prove our superiority, will you concede the point?"

Silence fell, broken only by the whirr and hum of robotic metabolisms.

"If you could so prove, we will certainly concede your status as our masters," Sand-in-the-gears said at last.

"Gracious, I should think so!" Magnan jerked his rumpled lapels into line. "For a moment, Retief, I confess I was beginning to feel just the teeniest bit apprehensive-"

"You have one minute to, prove your superiority," Broken Gla.s.s said flatly.

"Well, I should think it was obvious," Magnan sniffed. "Just look at us."

"Indeed, we've done so. We find you little, silly, crude, tender, apprehensive, and harmless."

"You mean-?"

"It means we'll have to do something even more impressive than standing around radiating righteous indignation, Mr. Magnan."

"Well, for heaven's sake," Magnan sniffed. "I never thought I'd see the day when I had to prove the obvious ascendancy of a diplomat over a donkey engine."

"We are waiting," File-on-steel said.

"Well, what do they expect?" Magnan yelped. "It's true they're bigger, stronger, faster, longer-lived, and cheaper to operate; and of course they have vast memory banks and can do lightning calculations and tricks of that sort- which, however, can hardly compare with our unique human ability to, ah, do what we do," he finished in a subdued tone.

"What do you do?" Red-eye demanded.

"Why, we, ah, demonstrate moral superiority," Magnan said brightly.

"Shilth was right about your sense of humor," Retief said admiringly. "But I think we'd better defer the subtle jests until we discover whether we're going to survive to enjoy the laugh."

"Well, for heaven's sake, do something, Retief," Magnan whispered, "before they make a terrible blunder." He rolled his eyes sideways at a scythe-like implement hovering as if ready to shear at any instant through the volume of s.p.a.ce he occupied.

"Time is up," Broken Gla.s.s said. The machines surged forward. The scythe, sweeping horizontally, clanged against the descending cleavers as Retief and Magnan jumped aside from the rush of a low-slung tree mower with chattering blades. The latter swerved, collided with a ma.s.sive punch press, one of whose piston-like members stabbed through the side of a ponderous masonry-wrecker. It wobbled, did a sharp right turn, and slammed into the cast-concrete wall, which cracked and leaned, allowing a ma.s.sive beam to drop free at one end, narrowly missing Magnan as he rebounded from the flank of a charging garbage-shredder. The falling girder crashed across the midsection of the latter machine with a decisive crunch!, pinning the hapless apparatus to the spot. It clashed its treads futilely, sending up a shower of concrete chips. The other machines cl.u.s.tered around it in att.i.tudes of concern, the Terrans for the moment forgotten.

"Hsst! Retief! This is our chance to beat a strategic withdrawal!" Magnan stage-whispered. "If we can just make it back to the elevator-"

"We'll find Shilth waiting at the top," Retief said. "Mr. Magnan, suppose you find a comfortable spot behind a packing case somewhere. I'm not quite ready to leave yet."

"Are you insane? These bloodthirsty bags of bolts are ready to pound us to putty!"

"They seem to be fully occupied with another problem at the moment," Retief pointed out, nodding toward a posthole digger which was fruitlessly poking at the end of the beam which had trapped its fellow. The scythe-armed robot was as busily sc.r.a.ping at the ma.s.sive member, without result. The ranks parted to let a heavy-duty paint-chipper through; but it merely clattered its chisel tips vainly against the impervious material. And all the while, the pinioned machine groaned lugubriously, sparks flying from its commutator box as it threshed vainly to pull free.

Retief stepped forward; Red-eye swiveled on him, raising a large mallet apparently designed for pounding heavy posts into hard ground.

"Before you drive home your argument," Retief said, "I have a proposal."

"What proposal?"

"You don't seem to be having much luck extricating your colleague from under the beam. Suppose I try-"

"One minute. I will lift the beam," a deep voice boomed. A ma.s.sively built loading robot trundled forward, maneuvered deftly into position, secured a grip on the concrete member with its single huge arm, and heaved. For a moment, nothing happened; then there was a sharp clonk! and a broken duralloy torque rod dangled from the lifter's forged-steel biceps. The girder had not stirred.

"Tough luck, old fellow," Retief said. "My turn."

"Good heavens, Retief, if that cast-iron Hercules couldn't do it, how can you hope to succeed?" Magnan squeaked from his corner.

"You have the ability to help our colleague?" Broken Gla.s.s demanded.

"If I do, will you follow my orders?"

"If you can do that which we cannot do, your superiority is obvious."

"In that case, just pull that bar out of there, will you?" Retief pointed to a four-inch-diameter steel rod, twenty feet long, part of a roller a.s.sembly presumably once used in loading operations. A stacking machine gripped the rod and gave it a firm pull, ripping it free from its mountings.

"Stick one end under the edge of the beam, like a good fellow," Retief said. "You there, jackhammer: Push that anvil under the rod, eh?" The machines complied with his requests with brisk efficiency, adjusting the lever as directed, with the fulcrum as close as possible to the weight to be lifted.

"Retief-if you couldn't even lift the lever, how are you going to..." Magnan's voice faded as Retief stepped up on the tread-skirt of a sandblaster and put a foot on the upangled long arm of the jury-rigged prybar. Steadying himself, he let his full weight onto the rod. Instantly, it sank gracefully down, lifting the multi-ton beam a full half inch from the depression it had imprinted in the garbage-shredder. The latter made a clanking sound, attempted to move, emitted a cascade of electrical sputterings, and subsided.

"He's ruptured himself!" Magnan gasped. "Poor thing. Still, we've done our part."

The other machines were maneuvering, making way for a squat cargo-tug, which backed up to the victim but was unable to get in position to attach its tow cable. A dirt-pusher with a wide blade tried next, but in the close quarters failed to get within six feet of the disabled machine. The others had no better luck.

"Mr. Magnan, find a length of cable," Retief called. Magnan rummaged, turned up a rusting coil of braided wire.

"One of you robots with digits, tie one end of the cable to the patient," Retief said. "Cinch the other up to something that won't give."

Two minutes later the cable was stretched drum-tight from a ma.s.sive stanchion to the cripple, running between closely s.p.a.ced paired columns.

"Next, we apply a transverse pull to the center of the cable," Retief directed.

"They can't," Magnan wailed. "There's no room!"