The rush of the ship threw her from her feet, and the hot coffee spilled from the pot and scalded her. She screamed. "Now what?" "I'm burned." "Coffee spill? Why didn't you put it down?" "I wish I'd spilled it on your face," she snapped. "Mind taking these irons off so I can get some isopicrine for the burn?" He tossed her the key. "If you run now, you'll starve before you get anywhere," he told her. "But stay out of my way. We're on the trail of Murdoch's Hoard." The thrumming whistle came in clear and strong as Benj headed into the thick fog. And as they drove forward at a wild speed, Benj tinkered with the detector. He picked up Cal's emitted signal easily and clearly, but was unable to get a response from the other source. He considered, and came to the conclusion that the other resonator might be outside of Cal's range of transmission and therefore inoperative as yet. Knowing Hellion Murdoch's personality by comparison to his own devious way of thinking, he knew that a world-wide broadcast of the response-signal would have been unnecessary. A general location within a hundred miles would have been good enough. So having no goal but Cal's signal, Benj turned the nose of his flier upon Cal's sharp, vibrating tone and drove deeper and deeper into the fog-blanket of Vilanortis. * * * * * As for Cal, he'd awakened by the clock and had tuned up his resonator before taking off. Immediately after making the initial adjustments, and tuning the Key a bit, the response came in strong and clear. Cal lifted the flier and began to trace the source. At almost full throttle he went on a dead straight line for Murdoch's Hoard. He wondered whether his signal were being followed, and suspected that it was. He knew, however, that no one was in possession of the technique of receiving the response, and therefore he drove at high speed. If he could arrive before the others, he would be able to establish his claim on Murdoch's Hoard, whatever it might be, or perhaps remove it if it were not too bulky. Once he established the direction of the response, Cal wisely turned his equipment off. That would forestall followers, and he could snap the gear on and off at intervals until he came close to the site of the famous Hoard. Benj swore as the signal ceased. But prior to its cessation, there had been a strong indication as to the relative motion of Cal's ship. He continued by extrapolation and went across the chord of the curve to intercept the other ship at some position farther along. Tinker smiled openly. "Cal isn't ignorant," she said. "Turning that thing off isn't going to help at all," responded Benj. "I've got Cal's original junk in the ship. I don't know the technique of finding the real Hoard, but I've been thinking that following the Key in Cal's ship might be possible. After all that's a cavity resonator too, you know." "Sure it is. But if you can't follow the Hoard resonator, how can you follow Cal's?"