 What would've happened if Alan had not made it to the switch?
Frowning, worrying about the sounds, Alan momentarily forgot to watch his step until his foot suddenly plunged into an ant hill, throwing him to the jungle floor. Then, through the trees he saw the clearing of the camp site, the temporary home for the scout ship and the eleven men who, with Alan, were the only humans on the jungle planet, Waiamea. Without pausing to think, Alan leaped back, and fell sprawling over a bush just as one of the robots rolled silently up from the right, lowering its blaster barrel to aim directly at his head. If I can just hold out until morning, when the big ship arrives ... The metal killers, tuned to blast any living flesh, would murder them the instant they stepped from the ship! In the movement, his elbow struck the top of a small earthy mound and he was instantly engulfed in a swarm of locust-like insects that beat disgustingly against his eyes and mouth. The planet's double moon had risen and he could see a robot rolling slowly across the clearing in his general direction, blasting indiscriminately at whatever mind impulses came within its pickup range, birds, insects, anything. Apparently the robot hadn't sensed him yet, but Alan didn't know what the effective range of its pickup devices was. He thought of a brown-haired girl crowding with the others to the gangway, eager to embrace the new planet, and the next instant a charred nothing, unrecognizable, the victim of a design error or a misplaced wire in a machine.
 The next group of people would have been caught by surprise and killed.
 The robots would have gone on living unnoticed by people, doing as they wished with the planet.  The next group of people would have been caught by surprise and killed.  Pete would have been the last hope of the people on the planet's surface.  Peggy would have had to build new radio transmitters after the old ones were destroyed.