The Devil's Den owner gave a little shrug and wave of his hand. Dave stared at him with admiration in his eyes, but the look was forced, for in his heart Dave felt only loathing, disgust, and cold anger for the man. So that was how Air Vice Marshal Bostworth's agent disappeared? God bless Freddy Farmer for his sudden hunch about thinking as well as acting as a German. If it hadn't been for Freddy he might have let go a few choice words in English, himself. And then he and Freddy would have mysteriously disappeared. A deadly snake if one ever crawled. That indeed was Serrangi, of the Devil's Den. Deadly, and clever, too. He knew what had happened to Bostworth's agent all right. Ten to one he had killed the man with his own hand when the attacker had reported that English had been cried out. But Serrangi was clever enough not to admit as much. No, not even to a pair who seemingly had proved they were a couple of Adolf Hitler's own paid killers.

"And so, it was only good sense for me to test you two in the same manner," Serrangi's voice broke into Dave's thoughts. "Of course I felt certain of you, but it was best to make sure. So, enough of this kind of talk. Let us speak of other things. The flight that must be made to the north for one thing. But first, have you two flown in this part of the world?"

Dave was tempted to lie, but on second thought decided that for once the truth might serve them better.

"No," he said just as Freddy started shaking his head. "We have done all our flying in Europe. But why is it important we have experience flying here in the Far East?"

"It is not important," Serrangi said. "It might perhaps be a bit helpful if you knew some of the country out here. That, however, is only a matter of opinion. I do not fly, but I suppose that flying is much the same in any part of the world?"

"Depends on the pilot," Freddy Farmer spoke up, and let it go at that.

"Of course," Serrangi grunted, and drew a roll of paper from inside his jacket. "Here," he continued, "is a map of this part of the world. As you will see it is well marked, and contains much data that one would not find on other maps of the same section of the world. Here, have a good look at it."

Serrangi unrolled a fair sized map and handed it to Dave. The American R.A.F. Flight Lieutenant took it in hands difficult to keep from trembling. Then he swiveled around a bit in his chair, and held it so that Freddy could look at it too. They did that little thing together and within two split seconds their hearts were hammering with suppressed excitement, to say nothing of amazement. The map was of the entire Malay Peninsula, Thailand, Burma, and a part of China as far north as Chungking. It was indeed a fine map. It was a perfect map for a pilot, because it contained countless little bits of information a pilot would like to know when flying over any of the territory. In fact, the information had been jotted down by some one who was obviously a pilot. And when Dave peered hard at the countless little margin notes and signs a cold lump of lead seemed to form in his stomach, and there was a great sickness in his brain. Beyond all question the person who had made the notes and signs was expertly acquainted with the way in which R.A.F. navigation maps are marked. In short, no less than an R.A.F. pilot had prepared this map he and Freddy Farmer stared at.

"It was a pilot who made this map, was it not?" Freddy Farmer suddenly shot out the question.

Serrangi beamed and looked very pleased.