But my description is futile. The important thing was not what we saw, but what we _felt_! A curiously unpleasant sensation of helplessness, and of strange horror, came over me. I felt as if I were stealing a forbidden glimpse of an ancient and incredible hell! Fear swept over me--alien, inconceivable terror--like a keen and bitter wind that numbed my brain! I felt the horror of a sentient force, utterly inhuman, devoid of all human knowledge or understanding, as cold and remote as the frozen night of space! It was terrible--an intangible _aura_ of fear that reached out of that pit and tugged at our souls with the icy hand of stark horror! I can give the world no conception of the overwhelming terror of it! Nor would I if I could, for such things are better forgotten. I dropped my rifle and clenched my hands, trembling. I braced my feet as though against the force of a physical wind that was striving to carry me toward that abyss of nebulous horror-light! I looked at Sam. He stood very still, leaning back, with hands raised and jaw dropped. In his eyes was the look of the fresh and innocent soul that struggles with a pitiless terror that it cannot know or understand! Such a look I had never seen before--and God grant that I may never see it again! 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.