"Not likely," said Sam thoughtfully. "He wanders around too freely, and he seems unused to the presence of human beings. Besides, no men would be likely to live here long without shelter. And I've seen no sign of any house or hut."
"Could he belong to a being that wasn't human?"
"No," replied Sam with certainty. "Only human beings have been able to domesticate dogs. If a dog is here, a human being was once here. That's definite."
"He would make a good pet," said Mark longingly.
"Not that one. Maybe I should have got you a dog long ago. It might have been just the kind of companionship you needed. But you can't make a pet of this animal. He's been away from people too long, and he's developed some mean habits." And he added mentally, "Like me."
"I could train him," said Mark. "He wouldn't be any trouble at all, Pop. I'd train him and feed him, and he'd be just like one of us. And—and like you say, Pop, it wouldn't be so lonely for me."
Kids don't give up easily, thought Sam. All the same, he had an idea that with this dog all the persistence in the world would be useless. He shrugged, and said simply, "We'll see." And then they went into the ship to eat.
All through the meal he could tell that Mark was thinking about the dog. The boy's thoughts seemed to affect his appetite. For the first time, he left some of his proteinex on the plate.
"I'm not very hungry today," he said apologetically. "Maybe—" He looked inquiringly at his father.