Asimov's Future History Volume 1 by Isaac Asimov

Expedition. Are you sure? They may be subrobotic machines. Ten years is a long time as far as robot-types are concerned, you know.”
    “No, they’re robots. I’ve spent all day with them and I know. They’ve got positronic brains: primitive, of course.” He placed the map in his pocket. “Let’s go down.”
     
    The robots were on the lowest sublevel – all six of them surrounded by musty packing cases of uncertain content. They were large, extremely so, and even though they were in a sitting position on the floor, legs straddled out before them, their heads were a good seven feet in the air.
    Donovan whistled. “Look at the size of them, will you? The chests must be ten feet around.”
    “That’s because they’re supplied with the old McGuffy gears. I’ve been over the insides – crummiest set you’ve ever seen.”
    “Have you powered them yet?”
    “No. There wasn’t any reason to. I don’t think there’s anything wrong with them. Even the diaphragm is in reasonable order. They might talk.”
    He had unscrewed the chest plate of the nearest as he spoke, inserted the two-inch sphere that contained the tiny spark of atomic energy that was a robot’s life. There was difficulty in fitting it, but he managed, and then screwed the plate back on again in laborious fashion. The radio controls of more modern models had not been heard of ten years earlier. And then to the other five.
    Donovan said uneasily, “They haven’t moved.”
    “No orders to do so,” replied Powell, succinctly. He went back to the first in the line and struck him on the chest. “You! Do you hear me?”
    The monster’s head bent slowly and the eyes fixed themselves on Powell. Then, in a harsh, squawking voice – like that of a medieval phonograph, he grated, “Yes, Master!”
    Powell grinned humorlessly at Donovan. “Did you get that? Those were the days of the first talking robots when it looked as if the use of robots on Earth would be banned. The makers were fighting that and they built good, healthy slave complexes into the damned machines.”
    “It didn’t help them,” muttered Donovan.
    “No, it didn’t, but they sure tried.” He turned once more to the robot. “Get up!”
    The robot towered upward slowly and Donovan’s head craned and his puckered lips whistled.
    Powell said: “Can you go out upon the surface? In the light?”
    There was consideration while the robot’s slow brain worked. Then, “Yes, Master.”
    “Good. Do you know what a mile is?”
    Another consideration, and another slow answer. “Yes, Master.”
    “We will take you up to the surface then, and indicate a direction. You will go about seventeen miles, and somewhere in that general region you will meet another robot, smaller than yourself. You understand so far?”
    “Yes, Master.”
    “You will find this robot and order him to return. If he does not wish to, you are to bring him back by force.”
    Donovan clutched at Powell’s sleeve. “Why not send him for the selenium direct?”
    “Because I want Speedy back, nitwit. I want to find out what’s wrong with him.” And to the robot, “All right, you, follow me.”
    The robot remained motionless and his voice rumbled: “Pardon, Master, but I cannot. You must mount first.” His clumsy arms had come together with a thwack, blunt fingers interlacing.
    Powell stared and then pinched at his mustache. “Uh... oh!”
    Donovan’s eyes bulged. “We’ve got to ride him? Like a horse?”
    “I guess that’s the idea. I don’t know why, though. I can’t see – Yes, I do. I told you they were playing up robot-safety in those days. Evidently, they were going to sell the notion of safety by not allowing them to move about, without a mahout on their shoulders all the time. What do we do now?”
    “That’s what I’ve been thinking,” muttered Donovan. “We can’t go out on the surface, with a robot or without. Oh, for the love of Pete” – and he snapped his fingers twice. He grew