"I can tell you that much," was the officer's reassurance; "and then you're no better off. It's of vast importance and would be of incalculable value to our enemies if it fell into their hands."
"Then there's only one explanation of your proposition," Irving concluded. "You will change the dots and dashes so that they will convey information different from that originally intended."
"Good!" exclaimed the colonel. "You'll do all right. Are you willing to undertake it?"
"I am," said Irving.
"Very well. So far so good. Now I'm going to test your nerve some more. Look out, for this is going to be a corker. If you drop, you'll drop hard."
"I'm waiting," said the boy, with a kind of gritty grin.
"All right. Would you dare make a descent with a parachute from an altitude of several thousand feet?"
This was a tester, indeed. Irving knew it the instant the last word of the question left the colonel's lips, but he did not flinch.
"Of course, I ought to have some preparation for such a feat," he replied. "I've never been up in an aeroplane."
"To be sure," Col. Evans agreed, with a vigorous nod. "You'll get all the schooling necessary. You'll start out on the venture well equipped. I'm going to send you to the aviation field near brigade headquarters, and there you'll learn to do your umbrella stunt. Then you'll come back here and go through some more preliminaries. The work of a spy, you see, is just as much of a science as the handling of an army."