"Wait!"
Again the engines were shut down to permit Fred to hear more clearly.
"The other plane and the ship are talking again, but I can't make it out," he explained. "It's all garbled, and I can only get a word here and there. Sounds like some sort of a code. By Jingo! It is! They're evidently talking to some other ship, and one friendly to them, at that. Conversation don't make sense at all."
He listened intently for a few moments and then gave a grunt of disgust. "They've stopped," he said. "Nothing more doing."
However, this was to be Fred's busy day, and only another short interval elapsed when something came to his ears that caused him to straighten up instantly to the closest attention.
Don, sitting near him and watching him, saw his eyes widen perceptibly, as though he was incredulous of what he heard. For several seconds he sat in the same position, not a muscle of his tense countenance changing, and then unconsciously his right hand went out toward his sending key. It rested there, however, and he sat immovable, making no effort to throw on the switch to connect the power necessary to send out a radio.
"Here," he said at last, clapping the earpieces onto the head of the surprised Don. "You don't know the radio code, but just raise and lower your hand with the length of each sound you hear. I don't know whether I'm hearing straight or have gone looney."
It was a moment before Don could distinguish anything, for he was not trained to the sound of the radio; but after an interval he suddenly raised his hand, then dropped it again, raised it and dropped it, at varying intervals in time with the short and long sounds he heard, and resembling in his actions some sort of an automatic contrivance more than a human being.
For he could neither understand nor interpret what he was, however, merely verifying to the astonished Fred.
"Do you know what that is?" the latter asked of the other two, who now were as interested as the mystified Don was.