Perhaps Alan felt what once was called a hunch, a premonition, the presage of evil which I think comes strangely to us more often than we realize. Whatever it was, we had no time to act upon it. The tunnel-mouth which had caused Alan's apprehension was about a hundred feet away. It was a ten-foot, yawning hole in the cliff. Perhaps Alan sensed a movement in there. As I turned to look at it a great, hairy human arm came out of the opening! Then a shoulder! A head! The giant figure of a man came squeezing through the hole on his hands and knees! He gathered himself, and as he stood erect, I saw that he was growing in size! Already he was twenty feet tall compared to us--a thick-set fellow, dressed in leather garments, his legs and arms heavily matted with black hair. He stood swaying, gazing around him. I stared up at his round bullet head, his villainous face. He saw us! Stupid amazement struck him, then comprehension. He let out a roar and came at us! CHAPTER V Glora shouted, "Into the tunnel! This way!" She held her wits and darted to one side, with Alan and me after her. We ran through a narrow passage between two fifty-foot boulders which lay close together. Momentarily the giant was out of sight, but we could hear his heavy tread and panting breath. We emerged having passed him. He was taller now. He seemed confused at our sudden scampering activity. He checked his forward rush, and ran around the twin boulders. But we had squeezed into a narrow ravine. He could not follow. He threw a rock. To us it was a boulder. It crashed behind us. To him, we were like scampering insects; he could not tell which way we were about to dart. Alan panted, "Glora, does this lead out?" The little ravine seemed to open fifty feet ahead of us. Alan stopped, seized a chunk of rock, flung it up. I saw the giant's face above us. He was kneeling to reach in. The rock hit him on the forehead--a pebble, but it stung him. His face rose away. Again we emerged. The tunnel-mouth was near us. We reached it and flung ourselves into its ten-foot width just as the giant came lunging up. He was far larger than before. Looking back, I could see only the lower part of his legs blocked against the outer light. "Glora! Alan, where are you?" For a moment I did not see them. It was darker in this tunnel of broken rocky walls, and jagged arching roof than outside. Then I heard Alan's voice: "George! Over here!" They came running to me. For a moment we stood, undecided. My eyes were becoming accustomed to the gloom. The tunnel was illumined by a dim phosphorescence from the rocks. I saw Alan fumbling for his vials, but Glora stopped him. "No. We are the right size." We were about a hundred feet back from the opening. The giant's legs disappeared. But in a moment the round, light hole of the exit was obscured again. His head and shoulders! He was lying prone. His great arms came in. He hitched forward. The width of his expanding shoulders wedged.