"But, Roger!" exclaimed Tom.
Bernard smiled. "I understand, Roger. Sometimes I forget that I'm an old man. And when you've already tasted the excitement of space travel, talk like mine must seem rather dull." He stood up and faced the three cadets. "It's been very pleasant, Corbett, Astro, Roger. Now run along and get your rest. I'll just sit here for a while and watch the scenery."
"Thank you, sir," said Tom, "for the dinner—your company—and everything," he finished lamely.
There was a chorus of good-byes and the boys returned to their car. But there was little conversation now. Gradually, the lights in the cars dimmed to permit sleep. But Tom kept listening to the subdued click of the monorail—and kept wondering. Finally Roger, sleeping next to him, wakened for a moment.
"Roger," said Tom, "I want to ask you something."
"Wait'll the mornin'," mumbled Roger. "Wanta sleep."
"The way you acted with Bernard," Tom persisted. "You ate his dinner and then acted like he was poison. Why was that, Roger?"
The other sat bolt upright. "Listen," he said. "Listen!" Then he slumped back in his chair and closed his eyes. "Lemme sleep, Corbett. Lemme sleep, I tell you." He turned his back and in a moment was making sounds of deep slumber, but Tom felt sure that Roger was not asleep—that he was wide awake, with something seriously bothering him.
Tom leaned back and gazed out over the passing plains and up into the deep black of space. The Moon was full, large and round. He could distinguish Mare Imbrium, the largest of Luna's flat plains visible from Earth, where men had built the great metropolis of Luna City. Farther out in the deep blackness, he could see Mars, glowing like a pale ruby. Before long he would be up there again. Before long he would be blasting off in the Polaris with Astro and with Roger—
Roger! Why had he acted so strangely at dinner?