"Oh, that's nothing the boys can't handle," said Helgers confidently. "In case they don't, we'll have to feel sorry for them and take our friend's sphere. Only have to split the treasure two ways, in that case," he added, moving up the slope. Borgain's answer was a grunt of surprise, for his captive had squirmed suddenly out of his clutch. The big man plunged forward recklessly with arms outstretched in the groping darkness. Penrun, desperately remembering the sickening drop at their feet to the pool three thousand feet below, backed against the rock. A flash of lightning. Borgain's ape-like arms were nearing him. Penrun lashed out at the darkened features. His knuckles bit deep into the flesh. He slipped aside as Borgain, mouthing fearful curses, rammed into the rock wall and rebounded. * * * * * Again the fumbling search. Another lightning flash. Penrun struck with frenzied desperation. Borgain took the blow behind the ear and staggered. He whirled, wild with fury, and charged vainly along the narrow ledge. "I'll get ye this time, damn your dirty carcass--ugh!" Guided by the sound of his voice, Penrun struck with all his strength. Borgain's nose flattened under the blow. He whirled half around. "I'll kill ye! I'll kill--help, help--a-ah!" Lost in the blackness he had plunged over the lip of the rock, thinking he was charging Penrun. Down into the yawning gorge his body hurtled, the sound of his frenzied, dwindling screams floating up eerily out of the black, ominous depths. Penrun crouched against the wall, sick and trembling. Irma, Helgers! He must hurry! He fumbled again for the pistols. They were gone. Crawling forward now, still shaken by his narrow escape from death, he gained the pathway. The rain was drumming wildly on the barren granite now, and the pitch-blackness was shattered only by ghastly lightning bolts. Guided by the flashes, he clambered up the slope and halted abruptly. The door of the space-sphere was open, and, silhouetted against the soft glow of light within it, was Irma, seated dejectedly with bowed head, heedless of the cold rain beating down upon her. Helgers was nowhere to be seen. Penrun dashed forward. "Irma, Irma!" he cried. "What has happened? Where is he?" She raised her head slowly and stared at him as at one risen from the dead. Then she burst into tears. "He said they had killed you--had thrown your body into the gorge," she sobbed. "I--I just didn't want to live after that. Are you hurt?" "Not a bit," he assured her fervently. "But where is Helgers?" "I pistoled him," she said quietly. "I had no choice. He came at me after I warned him to keep away. He fell over there among the rocks. Oh, Dick, let us hurry away from this mad place!" * * * * *