* * * * * Hours later the stooped figure of a shabby old man might have been seen stealthily re-entering the lonely workshop where the lights still burned brightly. Tom Forsythe lay rigid in the position in which Old Crompton had left him, and the dog growled menacingly. Averting his gaze and circling wide of the body, Old Crompton made for the table of the marvelous rays. In minute detail he recalled every move made by Tom in starting and adjusting the apparatus to produce the incredible results he had witnessed. Not a moment was to be wasted now. Already he had hesitated too long, for soon would come the dawn and possible discovery of his crime. But the invention of his victim would save him from the long arm of the law, for, with youth restored, Old Crompton would cease to exist and a new life would open its doors to the starved soul of the hermit. Hermit, indeed! He would begin life anew, an active man with youthful vigor and ambition. Under an assumed name he would travel abroad, would enjoy life, and would later become a successful man of affairs. He had enough money, he told himself. And the police would never find Old Crompton, the murderer of Tom Forsythe! He deposited his small traveling bag on the floor and fingered the controls of Tom's apparatus. He threw the starting switch confidently and grinned in satisfaction as the answering whine of the motor-generator came to his ears. One by one he carefully made the adjustments in exactly the manner followed by the now silenced discoverer of the process. Everything operated precisely as it had during the preceding experiments. Odd that he should have anticipated some such necessity! But something had told him to observe Tom's movements carefully, and now he rejoiced in the fact that his intuition had led him aright. Painfully he climbed to the table top and stretched his aching body in the warm light of the four huge tubes. His exertions during the struggle with Tom were beginning to tell on him. But the soreness and stiffness of feeble muscles and stubborn joints would soon be but a memory. His pulses quickened at the thought and he breathed deep in a sudden feeling of unaccustomed well-being. * * * * * The dog growled continuously from his position at the head of his master, but did not move to interfere with the intruder. And Old Crompton, in the excitement of the momentous experience, paid him not the slightest attention.