The shock wave rippled across the desert floor, flowed around the mountains and tunneled into Frenchman's Flat, setting off every shock-measuring instrument. Then came the ground wave, rolling through the earth like a gopher through a garden. Ditto for ground-wave measuring devices. Lastly, the sound boomed onto the startled scientists and soldiers like the pounding of great timpani under the vaulted dome of the burning sky. On mountain top observation posts, technicians turned unbelieving eyes north to the burgeoning pillar of smoke and dust, then yelped and swung optical and electronic instruments to bear on the fantastic column. In less than fifteen minutes, the test under preparation had been canceled, all equipment secured and the first assault waves of scientists, soldiers, intelligence and security men were racing north behind white-suited and sealed radiation detection teams cradling Geiger counters in their arms like submachine guns. Telephone lines were jammed with calls from Atomic Energy Commission field officials reporting the phenomena to Washington and calling for aid from West Coast and New Mexico AEC bases. Jet fighters at Nellis Air Force base near Las Vegas, were scrambled and roared north over the ground vehicles to report visual conditions near the purple pillar of power. The Associated Press office in San Francisco had just received word of the quake recorded by the seismograph at Berkeley when a staffer on the other side of the desk answered a call from the AP stringer in Carson City, reporting the blast and mighty cloud in the desert sky. One fast look at the map showed that the explosion was well north of the AEC testing ground limits. The Carson City stringer was ordered to get out to the scene on the double and hold the fort while reinforcements of staffers and photographers were flown from 'Frisco. Before any of the official or civil agencies had swung into action, the Circle T station wagon had rocketed off the ranch road and turned onto the oiled, county highway leading both to Carson City--and the now-expanding but less dense column of smoke. Johnny hunched over the wheel and peered through the thickening pall of smoke and dust, reluctant to ease off his breakneck speed but knowing that they had to find Hetty--if she were alive. Neither man had said a word since the wagon raced from the ranch yard. * * * * * There was no valid reason to associate the explosion with Hetty, yet instinctively and naggingly, Johnny knew that somehow Hetty was involved. Barney, still ignorant of his error of the oil drums, just clung to his seat and prayed for the best.