Plato explained patiently, "I didn't steal them. I made them myself."
"That's a lot of hot oxo-nitrogen. You hooked them some place, and if they ever find out—"
"Okay," said Plato, "if you don't want them, you don't have to take them. I can sell them to somebody else."
He allowed the young skeptic to try the goggles on and read by the light of the lamp. He knew little of the psychology of salesmanship, but with what might be called Platonic shrewdness, he sensed that once the prospect had experienced the joys of using the magic articles, he would never give them up.
The method worked. And soon Plato was richer by fifteen credits, instead of the ten or twelve he had hoped for.
He had a few other odds and ends, which he sold for as much as they would bring. After all, once he was out in space, he wouldn't need them any more.
In the middle of the next day, when the bell sounded the end of the class on Planetary Geography and it was time to go to the class on Animal Physiology, Plato picked himself up and walked out. One of the 'copter custodians looked at him suspiciously, but Plato didn't dignify the man by paying him direct attention.
He muttered to himself, "Always picking on me. I don't see why he can't send somebody else on his errands." It was better than the forged pass signed with the headmaster's name.
The pass itself came in handy when he bought a flight ticket. The ticket agent also stared at him suspiciously, but Plato was ready for him. He had prepared the slip of paper beforehand, tracing the headmaster's name laboriously from one of the lists of regulations attached to the wall.