Randall thought wistfully of his automatic, then nodded and followed McClellan down the corridor until the Australian stopped before a panel and jerked a thumb. Randall put his ear to the panel. For a moment he heard nothing. Then came a scream, a human scream that told of extreme agony; anguish beyond the unbearable pain of the ancient rack! Randall's face was chalky white as he turned, looked at McClellan for a split second, then rasped, "Let's go!" Together, they stepped back, then threw their combined weight against the panel. * * * * * When Jerome Jackson left his companions and crept sheepishly down the dim corridor with Randall's automatic clutched tightly in one pudgy hand, he came closer to hating himself than he ever had before in all his introverted, cowardly existence. His mind skimmed back over the miserable pages of his life. Born on the wrong side of the tracks in a mid-western city, he had lacked the innate ability and courage to grow above his inheritance. Rather, he had allowed his childhood handicaps to reduce the advantages of a series of lucky breaks to an extremely mediocre existence. He was a reasonably successful salesman only by virtue of a perpetual hang-dog look which brought a momentary feeling of magnanimity to his prospective customers. All in all, Jerome Jackson could not under any circumstance be expected to make the most of any situation, much less this almost foolhardy venture which Randall had precipitated. Jackson realized his own limitations as he crept miserably down the dim corridor, and was actually regretting that he, rather than Randall had the revolver, when he heard a sound behind one of the panels. Leaning close, he heard the low throb of massive machinery and the high-pitched whine of generators. He stopped and peered at the panel searchingly. He noticed a glowing stud set in the casement, and after a moment's hesitation he pressed it. The panel slid back smoothly. Jackson looked up and down the hallway, then stepped cautiously through the door. He found himself in a great high-domed room filled with ordered ranks of mighty but absolutely incomprehensible machinery, all humming enigmatic paens of power. Far down the serried ranks of gargantuan equipment he saw a light glinting on mighty crystal tubes. With hypnotic fascination, Jackson advanced slowly through the maze of humming mechanisms. The closer he came to those enigmatic tubes, the wider his pale eyes opened, until, as he stood at the base of the rod-high crystal cylinders, he looked like a puppet registering amazement and consternation. * * * * * Doctor Gerard held neither Jerome Jackson's cowardly fear of danger, nor Randall's contempt for it. While there were important scientific facts to be learned, danger didn't count. It just didn't exist insofar as he was concerned.