"George--" Lea faintly screamed. Her hand pressed her breast in terror as she shrank back against him. From around a nearby boulder a tremendous insect had come scuttling--a monstrous, reddish oblong thing, with a pinched body twenty feet in length and crooked jointed legs. With huge waving feelers, it stood for an instant motionless. Its great compound eyes, like clusters of tiny lanterns, glared balefully. And then without warning it came lunging at them! * * * * * Carter and the girl scrambled to their feet. The monstrous insect came with scuttling, scratching tread. Its antennæ, waving from the top of its ugly round head, furiously lashed. The mandibles of its great jaws worked as though with anticipation of devouring these tiny victims. "Lea--this way--jump--" They scurried sidewise. It flashed to Carter that they must take the drug--the enlarging drug--grow large to fight this horrible adversary. But there was no time now to get out the vial. Frantically they darted behind a little group of rocks. The huge red insect, like a charging bull, went past them. Then, fifty feet away, it stopped; reared up on its two hind legs as though puzzled. The luminous radiation from the rocks showed it more plainly now--long bulging body with six crooked legs; body pinched in the middle grotesquely like a spindly waist so small that it seemed as though the twenty-foot body might break in half. "It doesn't see us, George--" "Quiet!" They crouched among the rocks. There seemed no place else they could hide. Could they out-distance the horrible thing in a straightaway run? Carter did not think so; certainly he did not dare try it. He was fumbling with the drug-vial now. And then the monstrous insect saw them! It whirled; dropped to its six legs. The two great compound eyes again were glaring; and now on the top of its flattened, smooth-shelled head, near the sockets of the waving feelers, three other little eyes were visible--gleaming spots of light. "Here, Lea--take these pellets--quickly--" The giant insect was coming forward again, more slowly this time as though cautiously to stalk its tiny prey. Carter dropped two of the pellets into the trembling girl's extended palm; and took two himself. They were the violet ones--the diminishing drug. In the panic of the moment he could not select the others. His head reeled as he took the double dose, but he clung to Lea. In the swaying phantasmagoria of the luminous scene, he was aware that the monstrous scuttling thing again was charging head on. The rocks here were swaying, enlarging with a new acceleration, the spaces between them rapidly opening up.