Tom Raymond and Jack Parmly looked first at one another and then at the major. He had been smiling at their wonderment, but he was now serious, and regarded them gravely.
"Do you mean we have to do something to help catch this spy?" asked Tom.
"I'd like a hand in that!" exclaimed Jack. "I saw him first—he's my meat!"
"Well, get him if you can, boys," said the Frenchman. "But I did not come here to talk so much about him as about yourselves. The spy is a danger and a menace, but we know him and if he goes too far we can put out our hands and drag him back.
"No, what I referred to is more dangerous than merely trying to catch a spy at his sneaking work. I will tell you." The major suddenly left his seat near the window of the boy's room, and quickly opened the door leading to the hall. The passage was empty.
"I rather thought there might be an eavesdropper," the major explained. "I was followed here, though I don't believe the spies know my mission. However, it is best to be careful. With your permission I'll pull down the shade. There may be spies stationed across the street who, with powerful glasses, might look through the window and gather something of what we say by reading our lips. It has been done."
"The Germans don't leave much untried," commented Tom. "But what is it you want us to do, if it isn't trying to trail the spy?"
The major motioned them to draw closer to him, and then, leaving the door into the hall open, so that he could note the approach of any one, he whispered:
"You are to be two members of a picked company of air scouts who are to go out, discover the big German gun, and destroy it!"
"Whew!" whistled Tom, after a moment of thought during which he and Jack exchanged quick glances.