The leaders of each nation spoke to their people, and the world waited in tense silence. One day an enormous sphere appeared and landed. The creatures that emerged couldn't be clearly discerned because they were in space-suits which gave them comfortable air-pressures and what was to them breathable atmosphere. They were four-legged creatures but could walk on two, if necessary.
A delegation of picked dignitaries started to show them our world, our customs, the way we dressed, what we lived in, what we ate. Almost immediately the strangers turned and left our world.
Within two days Earth was in bondage.
The old space veteran stopped. He looked around at the tense faces.
"We found out later," he said. "It was the banquet they watched on a film which we ran off, that did it. There was a scene where a waiter brings in a whole roast pig with an apple in its mouth and then it's eaten."
All the boys drew a deep horrified breath. The old man nodded heavily. "Well," he said, "how were we to know these beings from outer space had evolved from pigs, or creatures very similar?" He sighed, and stood up. "Well, maybe in fifty years they'll feel we're advanced enough for freedom." He smiled. "I'll leave you to your telepathy classes and conditioning."
He moved toward the door and a portion of glass wall slid aside to let him through. But before he exited he turned and said softly, "Now don't let it get you, boys. Being exhibited in a zoo isn't too bad. Serve your time and you'll get servant status like me and get out into space."
He waved and walked out through the spectators gathered around the glass cage. They moved aside to let him through, staring at him with brilliant brown eyes, their snoutlike noses twitching in sympathy and kindness, their pig-like faces gentle with the expression a man gives a trained dog.