“That’s strong language, Mortlake,” said the young officer, drumming the table with his fingers impatiently.  Honorable and upright in all his dealings, the young officer had no liking for the business in hand.  Yet it was his duty to see the thing through now, unpleasant as it promised to be.

“Strong language?” echoed Mortlake.  “Yes, it is strong language, but not a bit more emphatic than the case warrants.  Did you know that for some days past a German spy has been in Sandy Beach?”

“No.  Certainly not.”

“Well, there has been.  He visited this plant with proposals to turn over our aeronautic secrets to his government, but we refused to have anything to do with his scheming.”

“Yes, very good.  Go on, please.”  The young officer felt that Mortlake was approaching the climax of his story.

“One of our men,” resumed Mortlake, in even tones, in which he cunningly managed to mingle a note of regret, “one of our men took upon himself—­loyal fellow—­to watch this spy.  He reported to me some days ago that the man was in negotiation with young Prescott.”

“Good heavens!”

“I know it sounds incredible, but we are dealing with facts.  Well, more than this, my zealous workman ascertained that young Prescott is to meet this foreign agent at nine o’clock to-night on a lonely road, and is there to hand over to him the complete plans and specifications of the Prescott aeroplane.”

“It’s unbelievable, horrible.  And in the face of this, do you mean to say that the boy would dare to keep up his apparent negotiations with the United States?”

“That’s just the worst part of it, as I understand it,” rejoined Mortlake.  “The negotiations with this foreigner would, of course, be presumed by young Prescott to be secret.  This being so, he would, if successful in the tests, sell his ideas to the United States also, without mentioning the fact that they had already been bought and paid for.”

“Monstrous!”

“Just what I said when I heard of it.  I could not believe it, in fact.  The boy has always seemed to be all that was upright and honest.  It just shows how we can be mistaken in a person.”

“I cannot credit it yet, Mortlake.”

“It was to give you proof positive that I summoned you here.  We will take an automobile out to the spot where young Prescott is to meet the foreign agent.  Of course, our arrival will be so calculated as to give us time to secrete ourselves before Prescott and the other meet.  Are you willing to let your estimate of young Prescott stand or fall by this meeting?”

“I am, yes,” replied Lieut.  Bradbury, breathing heavily.  “The young scoundrel, if he is caught red-handed, I will see if there is not some law that will operate to take care of his case.”

Mortlake could hardly conceal a smile.  His plan to ruin Roy was working to perfection.  In his imagination he saw the Prescott aeroplane eliminated as a naval possibility, and the field clear for the selection of the Mortlake machine.  Mentally he was already adding up the millions of profit that would accrue to him.