“You’re right,” he said. “Feather—beak—well up the evolutionary ladder. This place looks promising. I’ll start the camera.”

The swaying motion of the picture as the robot walked forward did not distract them: they had grown accustomed to it long ago. But they had never become reconciled to this exploration by proxy when all their impulses cried out to them to leave the ship, to run through the grass and to feel the wind blowing against their faces. Yet it was too great a risk to take, even on a world that seemed as fair as this. There was always a skull hidden behind Nature’s most smiling face. Wild beasts, poisonous reptiles, quagmires—death could come to the unwary explorer in a thousand disguises. And worst of all were the invisible enemies, the bacteria and viruses against which the only defence might often be a thousand light-years away.

A robot could laugh at all these dangers and even if, as sometimes happened, it encountered a beast powerful enough to destroy it—well, machines could always be replaced.

They met nothing on the walk across the grasslands. If any small animals were disturbed by the robot’s passage, they kept outside its field of vision. Clindar slowed the machine as it approached the trees, and the watchers in the spaceship flinched involuntarily at the branches that appeared to slash across their eyes. The picture dimmed for a moment before the controls readjusted themselves to the weaker illumination; then it came back to normal.

The forest was full of life. It lurked in the undergrowth, clambered among the branches, flew through the air. It fled chattering and gibbering through the trees as the robot advanced. And all the while the automatic cameras were recording the pictures that formed on the screen, gathering material for the biologists to analyse when the ship returned to base.

Clindar breathed a sigh of relief when the trees suddenly thinned. It was exhausting work, keeping the robot from smashing into obstacles as it moved through the forest, but on open ground it could take care of itself. Then the picture trembled as if beneath a hammer blow, there was a grinding metallic thud, and the whole scene swept vertiginously upward as the robot toppled and fell.