At last all was ready. The motor was started, and we pushed the plane out into the surf. A moment later, and she was skimming seaward. Gently she rose from the surface of the water, executed a wide spiral as she mounted rapidly, circled once far above us and then disappeared over the crest of the cliffs. We all stood silent and expectant, our eyes glued upon the towering summit above us. Hollis, who was now in command, consulted his wrist-watch at frequent intervals.

"Gad," exclaimed Short, "we ought to be hearing from him pretty soon!"

Hollis laughed nervously. "He's been gone only ten minutes," he announced.

"Seems like an hour," snapped Short. "What's that? Did you hear that? He's firing! It's the machine-gun! Oh, Lord; and here we are as helpless as a lot of old ladies ten thousand miles away! We can't do a thing. We don't know what's happening. Why didn't he let one of us go with him?"

Yes, it was the machine-gun. We would hear it distinctly for at least a minute. Then came silence. That was two weeks ago. We have had no sign nor signal from Tom Billings since.

Chapter 2

I'll never forget my first impressions of Caspak as I circled in, high over the surrounding cliffs. From the plane I looked down through a mist upon the blurred landscape beneath me. The hot, humid atmosphere of Caspak condenses as it is fanned by the cold Antarctic air-currents which sweep across the crater's top, sending a tenuous ribbon of vapor far out across the Pacific. Through this the picture gave one the suggestion of a colossal impressionistic canvas in greens and browns and scarlets and yellows surrounding the deep blue of the inland sea—just blobs of color taking form through the tumbling mist.