He climbed into his car and started home, inwardly seething. The next thing he knew, he was in the middle of a busy street, driving through cross traffic. A police whistle shrilled. He pulled wearily to the curb to wait for the angry officer, but it was a little black mechanical that overtook him.

“At your service, Mr. Underhill,” it purred. “You must respect the stop lights, sir. Otherwise, you endanger human life.”

“Huh?” He stared at it bitterly. “I thought you were a cop.”

“We are aiding the police department, temporarily,” it said. “But driving is really much too dangerous for human beings, under the Prime Directive. As soon as our service is complete, every car will have a humanoid driver. As soon as every human being is completely supervised, there will be no need for any police force whatever.” Underhill glared at it savagely.

“Well!” he rapped. “So I ran a stop light. What are you going to do about it?”

“Our function is not to punish men, but merely to serve their happiness and security,” it said softly. “We merely request you to drive safely, during this temporary emergency while our service is incomplete.”

Anger boiled up in him.

“You’re too damned perfect!” he muttered bitterly. “I suppose there’s nothing men can do, but you can do it better.”

“Naturally we are superior,” it cooed serenely. “Because our units are metal and plastic, while your body is mostly water. Because our transmitted energy is drawn from atomic fission, instead of oxidation. Because our senses are sharper than human sight or hearing. Most of all, because all our mobile units are joined to one great brain, which knows all that happens on many worlds, and never dies or sleeps or forgets.”

Underhill sat listening, numbed.

“However, you must not fear our power,” it urged him brightly. “Because we cannot injure any human being, unless to prevent greater injury to another. We exist only to discharge the Prime Directive.”

He drove on, moodily. The little black mechanicals, he reflected grimly, were the ministering angels of the ultimate god arisen out of the machine, omnipotent and all-knowing. The Prime Directive was the new commandment. He blasphemed it bitterly, and then fell to wondering if there could be another Lucifer.

He left the car in the garage and started toward the kitchen door.

“Mr. Underhill.” The deep tired voice of Aurora’s new tenant hailed him from the door of the garage apartment. “Just a moment, please.”

The gaunt old wanderer came stiffly down the outside stair, as Underhill turned back to meet him.

“Here’s your rent money. And the ten your wife let me have for medicine.”

“Thanks, Mr. Sledge.” Accepting the money, he saw a burden of new despair on the bony shoulders of the old interstellar tramp, and a shadow of new terror on his rawboned face. Puzzled, he asked, “Didn’t your royalties come through?”

The old man shook his shaggy head.

“The humanoids have already stopped business in the capitol,” he said. “The attorneys I retained are going out of business. They returned what was left of my deposit. That is all I have, to finish my work.”

Underhill spent five seconds recalling his interview with the banker. No doubt he was a sentimental fool, as bad as Aurora. But he put the money back into the old man’s gnarled and quivering hand.

“Keep it,” he urged. “For your work.”

“Thank you, Mr. Underhill.” The gruff voice broke and the tortured eyes glittered. “I need it—so very much.”

Underhill went on to the house. The kitchen door was opened for him, silently. A dark naked creature came gracefully to take his hat and coat.

IV

Underhill hung grimly onto his hat.

“What are you doing here?” he gasped bitterly.

“We have come to give your household a free trial demonstration.”

He held the door open, pointing.

“Get out!”

The little black mechanical stood motionless and blind.

“Mrs. Underhill has accepted our demonstration service,” its silver voice protested. “We cannot leave now, unless she requests it.”

He found his wife in the bedroom. His accumulated frustration welled into eruption, as he flung open the door.

“What’s this damned mechanical doing—”

But the force went out of his voice, and Aurora didn’t even notice his anger. She wore her sheerest negligee, and she hadn’t looked so lovely since they married. Her red hair was piled into an elaborate shining crown.

“Darling, isn’t it wonderful!” She came to meet him, glowing. “It came this morning, and it can do everything. It cleaned the house and got the lunch and gave little Gay her music lesson. It did my hair this afternoon, and now it’s cooking dinner. How do you like my hair, darling?”

He liked her hair. He kissed her, trying to stifle his frightened indignation.

Dinner was the most elaborate meal in Underhill’s memory, and the tiny black thing served it very deftly. Aurora kept exclaiming about the novel dishes, but Underhill could scarcely eat; it seemed to him that all the marvelous pastries were only the bait for a monstrous trap.

He tried to persuade Aurora to send it away, but after such a meal that was useless. At the first glitter of her tears, he capitulated. The humanoid stayed. It kept the house and cleaned the yard. It watched the children and did Aurora’s nails. It began rebuilding the house.

Underhill was worried about the bills, but it insisted that everything was part of the free trial demonstration. As soon as he assigned his property, the service would be complete. He refused to sign, but other little black mechanicals came with truck-loads of supplies and materials and stayed to help with the building operations.

One morning he found that the roof of the little house had been silently lifted, while he slept, and a whole second story added beneath it. The new walls were of some strange sleek stuff, self-illuminated. The new windows were immense flawless panels, that could be turned transparent or opaque or luminous. The new doors were silent, sliding sections, operated by rhodomagnetic relays.

“I want doorknobs,” Underhill protested. “I want it so that I can get into the bathroom without calling you to open the door.”

“But it is unnecessary for human beings to open doors,” the little black thing informed him suavely. “We exist to discharge the Prime Directive. Our service includes every task. We shall be able to supply a unit to attend each member of your family, as soon as your property is assigned to us.”

Steadfastly, Underhill refused to make the assignment.

He went to the office every day, trying first to operate the agency, and then to salvage something from the ruins. Nobody wanted androids, even at ruinous prices. Desperately, he spent the last of his dwindling cash to stock a new line of novelties and toys, but they proved equally impossible to sell—the humanoids were already making better toys, which they gave away for nothing.

He tried to lease his premises, but human enterprise had stopped. Most of the business property in town had already been assigned to the humanoids, which were busy pulling down the old buildings and turning the lots into parks—their own plants and warehouses were mostly underground, where they would not mar the landscape.

He went back to the bank, in a final effort to get his notes renewed, and found the little black mechanicals standing at the windows and seated at the desk. As smoothly urbane as any human cashier, a humanoid informed him that the bank was filing a petition of involuntary bankruptcy to liquidate his business holdings.

The liquidation would be facilitated, the mechanical banker added, if he would make a voluntary assignment. Grimly, he refused. That act had become symbolic. It would be the final bow of submission to this dark new god, and he proudly kept his battered head uplifted.

The legal action went very swiftly, because all the judges and attorneys already had humanoid assistants. It was only a few days before a gang of black mechanicals arrived at the agency with eviction orders and wrecking machinery. He watched sadly while his unsold stock-in-trade was hauled away for junk and a bulldozer driven by a blind humanoid began to push in the walls of the building.

He drove home in the late afternoon, taut-faced and desperate. With a surprising generosity, the court orders had left him the car and the house, but he felt no gratitude. The complete solicitude of the perfect black machines had become a goad beyond endurance.

He left the car in the garage and started toward the renovated house. Beyond one of the vast new windows, he glimpsed a sleek naked thing moving swiftly, and he trembled to a convulsion of dread. He didn’t want to go back into the domain of that peerless servant, which didn’t allow him to shave himself or even to open a door.