When they were inside the ship again, Mark said, "Guess I'd better get back to my arithmetic."
"In a minute," said Sam. "I want to talk to you first." He dropped wearily into a seat, although he had done nothing that should have tired him out. His son looked at him expectantly. "Mark, do you like traveling around with me?"
"Sure, Pop, I like to be with you."
"Not seeing anybody else? No other kids, no people of any kind? Just being with me, learning your lessons from tapes, and having your test papers corrected automatically? You don't get tired of it?"
Mark hesitated despite himself. Then he said loyally, "I'd rather be with you than anybody else. When Mom—when Mom died—I didn't want to see anybody."
"I know how you felt. But that was four years ago. You can't grow up alone. Now what you need to do is meet people, learn how they talk and think and feel. You can't learn those things from tapes, and you can't learn them from me."
Mark said stubbornly, "I like to be with you."
"I'm not much of a person to be with. Don't think I don't know it. I'm mean and surly, and my temper's getting worse by the day. I can't associate with people any more. But you can. I was thinking maybe I'd leave you—"
"No!" cried Mark.
"Not in an orphanage or anything like that. But I have some friends whose kids are growing up—"