The right side of the tracks

The Nodarians weren't planning a revolt. Nor had the planet been captured by aliens. If they were obstinately silent, it was simply because they now lived on ...
By ALBERT TEICHNER
Illustrated by SCHELLING
For the last week they had been hovering a half-million miles out from the Terra-scale planet and now all fifty men aboard the Probe were agreed that it was time to land and investigate the place at closer hand. Even Dr. Stern, the perennial pessimist, felt the inhabitants still looked human through the electroscope. While hopelessly blurred by such distance magnification, these two-legged, two-armed beings showed nothing dangerously different from men on any other member planet of the Galactic Glia.
But why did these seeming fellow creatures want to be by themselves in total isolation?
Every schoolboy knows that each of the ten thousand human planets signals all the others once each galactic hour—even if there is no information to exchange except the carrier signal itself. Just as each neuron in a brain maintains some electrical contact with every other. From this infinite openness of pathways, the schoolboy will explain to you, comes the adaptability of both the individual mind and human civilization in general, the ability to concentrate everything on whatever problem is at hand.
Yet here was Nodar refusing to answer the universal signals for years at a time. There was something menacing about this non-conformity and Supreme Council had carefully considered all possibilities before dispatching the Probe . These had boiled down to a painful set of alternatives: either an alien species, commencing the building of an empire, had seized the planet; or the Nodarians, turned primitive for some unknown reason, were hiding behind the wall of silence to mount their own attack on the rest of the human universe.
Alien seizure, my foot! Commander Linder told the rest of the crew now. Those are men down there, men working up some anti-social mischief we truly civilized people can't even imagine.