"I'm a spy myself," he said eventually, "so I think I have a good idea of both sides of the picture in this kind of business. A spy is regarded as the lowest form of worm in wartime, and he's usually shot five minutes after he is caught. But there have been a lot of spies who were brave and gallant men, and they took the job of going behind the enemy lines because that was the best way they could serve their country. But the type of spy such as we're dealing with now--the slinking rat who in peace-time becomes the citizen of another country, enjoys all of its advantages, and then turns on that country when his former country goes to war--well--he is in my opinion the rottenest form of vermin that ever existed. He doesn't rate the privilege of being shot when caught. He should be strung up by the thumbs, and skinned alive." "And even that's too good for him!" Captain Lamb echoed viciously. "Those who bite the hand that's feeding them deserve the worst of the worst. And man! Would I give my life just to get my hands on that skunk aboard the Indian, whoever he is!" Dave was slightly startled by the almost berserk rage in the redheaded Captain's voice. He glanced at Colonel Welsh and saw a look of pity and sympathy flit across the chief of U. S. Intelligence officer's face. That expression told much to Dave, and he glanced at Captain Lamb again. "You knew Jackson and Pollard, Captain?" he asked quietly. The Captain nodded and licked his lower lip. "I knew them both well," he said in a low voice. "Pollard was my dearest friend. We came from the same town. Played football together at Dartmouth before he changed over to the Naval Academy. They don't make them better than Jake Pollard was." "If it helps any," Dave said quietly, "I'll be thinking of you, Captain, _if_ and _when_ Farmer and I catch up with that dirty rat aboard the Indian." "Thanks," the redhead mumbled, and lapsed into brooding silence. Dave started to say something else to him, changed his mind, and turned back to Colonel Welsh. "I suppose you've got a plan of operation you want Farmer and me to follow, sir?" he asked. "I have the _start_ of a plan of operation," the senior officer replied gravely. Then with a helpless shrug: "But from there on you two will be on your own." CHAPTER FIVE _Silent Wings_ Dave waited for the man to continue, and when he didn't he put another question to him. "We start from scratch, sir, you mean?" he asked. "There isn't any kind of a clue for us to work on? You're stationing us aboard the Indian, of course?" "That's right," the chief of U. S. Intelligence replied with a nod. "The Indian is shy two flying lieutenants, and you two are going to fill the vacancies. Matter of fact, the Indian is also shy two machinists' mates, and they'll be put aboard too before she weighs anchor sometime the day after tomorrow." "Two of your men, sir?" Freddy Farmer spoke up, giving the Colonel a keen stare.