"Yeah, something like that," Dawson nodded with a shaky little laugh. "But I wonder, though. I mean, we've been here quite a spell, and we haven't bothered looking behind us. _If_ he's here, and has his gun, he's certainly had a lot of chances to let us both have it in the back. I wonder why not?" "Well, stop wondering!" Freddy Farmer muttered, and got to his feet. "Let's do as the vice-admiral orders, and get away from this place." "But fast!" Dave echoed with a grim nod. "Suddenly I've had all I want of California for a spell, anyway!" CHAPTER SIX _Invisible Killer_ With its four engines singing a song of power that would be sweet music to the ears of any pilot the Flying Fortress thundered its way southwestward through the night-darkened Pacific sky. The aircraft was on the automatic pilot, and both Dawson and Freddy Farmer sat outwardly relaxed at the controls, but inwardly on the alert for the slightest miss in any of the engines, or for anything that would indicate that all was not as it should be. The Los Angeles Air Forces base was six hours behind them. Another six and they should be over Hickam Field, on Oahu Island, waiting for the permission signal to land. Suddenly, with a little chuckle, Dawson broke the silence that had existed for some minutes between them. Freddy Farmer glanced across at him with a questioning frown. "What now, Dave?" he asked. "Us," Dawson replied, and chuckled again. "I guess we're getting old, Freddy. I mean, we seem to scare pretty easy these days. And I'll admit that I was as jittery as a hen on a hot stove until we got this Fortress off the ground, and into the air. I actually had little chills running up and down my back, as though I expected to feel a nice white-hot bullet cut into it at most any second. But heck! Not a thing happened. I didn't see a thing that looked Jap, did you?" "No, I didn't," Freddy Farmer replied. "But my imagination certainly gave me a lot of trouble. Every time one of those mechanics put a bag of mail aboard, or a case of those medical supplies we're taking over, I had a brief moment of feeling positive that he was a Japrat, buck teeth, and all. But, as you say, nothing happened." "Yeah," Dawson murmured, and peered out at the wall of night darkness that completely circled the aircraft. "Just another airplane ride for us. And that doesn't make me mad at all. I wonder if the field radioed Dago when we got off? Vice-Admiral Carter sure sounded plenty worried on that phone." "Yes, he ..." Freddy Farmer said, and then cut himself off short. "What's the matter, Freddy?" Dawson asked, as a sudden clammy sensation rippled through his chest. "Down there," young Farmer replied, and pointed off and down to the left. "Is that a light blinking, or am I seeing things?"