My gaze was drawn irresistibly back into that mantle of moving light. Even as I watched, a pillar of green flame, very bright and broad, thrust itself up through the wavering mist of violet fire, and into the crimson haze. It was like the slender head of some obscene green reptile. It reached up—incredibly! It writhed and twisted about! It was like a great serpent of fire. And it saw us!
It grew still with awful attention. Eternities seemed to pass as the dreadful thing hung there, motionless, like a vast frozen pillar of twisted emerald flame, like a column of curdled green fire, with curious throbbing changes in its brightness. I felt a weird force flowing out of it. And I knew that it was watching us!
"My God!" Sam muttered. "My God!" I looked at him again. His thin face was very white, and beaded with perspiration. He was mechanically mopping at his forehead with the red handkerchief, and staring at the mist of flame with the glaze of terror upon his eyes.
I struggled mightily to throw off the spell of amazement and terror—of alien and unutterable horror—that was grasping at my mind. It was a heart-breaking effort. I moved. I seized Sam's arm and shook it. He swayed drunkenly, with his eyes still on the awful lights. He was like one in a trance—like a man in a dream of death!
And I felt those icy fingers of unthinkable doom closing about my own mind. I was paralyzed again, with my eyes drawn back to the north. The snake's head of frozen green still throbbed strangely, and the flickering violet aurora still kept up its storm of varying motion, in the dim rosy haze into which the awful head was lifted.
Something was reaching toward us, out of the pit! I knew there was intelligence in it—a will, inhuman, and unthinkably strong! It was calling us, compelling us! I knew that in a few moments we could fight no more.
Suddenly a low sobbing sound reached us on that warm, humid south wind, a sound that wailed uncertainly behind us, and rose to a piercing shriek, and slowly died away into the distant south, echoing weirdly on hills and trees as it rolled and sank.
Sam started with a hoarse cry, and went off down the hill toward the north at a stumbling run—toward that abyss of alien horror! A moment more I struggled desperately, but that pitiless power overwhelmed me! I followed in his tracks!
And then, a clear rich voice reached me from beyond the hill—a shout in Xenora's rich and ringing tones. It had a clear human overtone of confidence and courage. "Come back, Melvin Dane! Come back, Sam!"
The old scientist stopped uncertainly, passing his hand dazedly before his brow. Abruptly the terror was gone from my mind! The love and the courage of the brave girl flowed into me. And suddenly, with the green light still pulsing through it, as though sent by a mighty heart, the terrible thing in the north dimmed slowly and faded away! Still the violet lances flickered through the rosy mist, but the green thing was gone—and we were free!