"Refraction-protract," she cried. Under her skillful guidance the car turned left, then right, to miss the oncoming beam by inches. The girl uttered a sigh of relief. "That was too close for comfort," she said. "Those refraction-protracts are disintegrating light rays stored up by the Red Desert sands and released by sudden changes in temperature. We'll have to watch ourselves." They drove on in silence. Questions were surging through Jimmy's brain, but he said nothing, waiting for the girl to explain. "Would it surprise you very much if I told you the man behind all this is Hamilton Garth?" He went slowly rigid. "Garth? But he--" "Told you he was trailing the Nebula. That was a neat way to divert suspicion from himself. You see, Garth, although a member of the _superiors_ class, has been having financial trouble with both of his companies lately, Crater City Trust, and Phobos Enterprises. Some of his investments went wrong; in particular, an expedition he financed to Pluto was never heard from again. He needed funds desperately and _pxar_ was his answer. "How he learned that your father's work in deciphering the _Chronicles_ was connected with this strange material, we probably shall never know. The important thing is he did find out and immediately took steps to acquire them. But even after he had them it was necessary to complete the cypher before he could learn the secret. Garth must have found a passage in some work other than the _Chronicles_ that led him to suspect vaguely the nature of the final revelation." Jimmy nodded slowly. "I see," he said. "And after Garth has located the supply of figurines, he intends to launch them on their parasitical work and sell the supply of _pxar_ he thus accumulates to the engineers. But neither the Martians nor the engineers would consent to such a diabolical plan." The girl smiled grimly and touched a stud on the dash, increasing the speed of the car. "Garth took care of that, too," she explained. "He planned to advertise all over Mars a sanitarium devoted to the cure of every conceivable kind of ill. It was to be located in the mountains beyond the Red Desert Country. Once a patient was admitted, his doom was sealed. "It was Garth, of course, who broke into the Crater City Museum, stole the three Thro-Pahl figurines and killed the night-watchman. Previously he had designed a fake Nebula signature card, and he left this behind at the scene of the crime. He's a member of the _superiors_ class, you must remember, and his hatred for the man who was making a mockery of that class was intense." * * * * * Dawn came up slowly, a reddish haze at first, then a brilliant glare that turned the canal into a glittering avenue of crimson reflections. They roared east along a canal that steadily grew narrower. Presently, far ahead, a depression became visible in the side wall. Up this depression a nature-formed ramp led to the upper level.