"There are those who feel it might consist of compacted hydrogen atoms." "Would it make much difference as long as we can use the heat?" Marta asked. "If we are not careful in tapping such a core--" Kotenko paused for a moment, considering the consequences--"we could turn the Solar System into a binary system." "I doubt that," Chandler said. "Besides, I don't plan to set off an X-bomb in the core." "The immediate problem," said Kotenko, "is to drill such a hole." "It will take some real engineering," Chandler admitted. "It will take more than engineering." Kotenko looked directly into Chandler's eyes. "Will you listen to a suggestion of mine?" "That's why I singled you out for the committee." "Forget a drill of super-dense metal." He leaned forward. "Use a device that will melt anything it comes into contact with, fuse the material into a casing and remove the heat conductivity from it so that it will remain solid. This device would sink toward the center of the Earth on a gravity drive principle. Your pressure traps would be force fields--controlled to allow surplus debris to spew out the top like an oil gusher." Kotenko settled back against the head rest. "Where would we get the energy to drive this device?" Chandler asked. "Thermo-nuclear power developing heat and thermo-electricity." "Then I would be taking a fusion bomb into the core of the Earth." "Yes, you would. You would have to maintain careful control from the surface." "And suppose the core is made of compacted hydrogen atoms?" Marta asked. Kotenko blew a long ribbon of smoke. "I doubt if there would be any danger unless we add the X-factor to the device." Marta started to speak, but an insistent electronic chiming interrupted. "Emergency deceleration," Chandler said calmly. Even before the "Fasten Your Seatbelts" sign flashed on, Chandler, Kotenko and Marta had the buckles clamped tight and were braced against the head rests of their chairs. Light beam generators whirred. The tubecar shuddered and lurched to a stop. The lights went out and a woman screamed somewhere. "There is no danger," the reassuring voice of the driver said over the speaker system. "There seems to be some trouble ahead." The lights flickered on dimly. "We are on our own power," Kotenko said. "The tube must be out up ahead." "Another avalanche?" asked Marta. A private car pulled up behind them and cushioned to a stop on their force field bumper. Chandler swiveled his chair around and looked through the front viewdome at the scene ahead. The tubeway was illuminated with faint emergency light panels for about two hundred feet. A Greyhound Tubecar and several private cars were stalled at that point. Beyond was blackness. Marta unbuckled her seat belt and stood up to see better. Chandler gazed up the slope of a towering peak alongside them. Deep snow glistened in the soft reflected light of the tube.