“It doesn’t depend entirely on you, Mark,” said Madera, appearing to read Mark’s mind. “Now let’s power up.” Mark felt the anxiety drain away. He pressed the power button he had discovered before, when the Starmen had been escaping from the pirates. The computer screen surged into life. The men cheered, and Madera smiled. Joe stretched exultantly and appeared to grow two inches taller. Zip’s brow remained furrowed. He showed little emotion. For him the time to exult would be when the asteroid had been diverted. This was only a vital step in the process. There were others ahead. Mark kept his eyes on the screen but spoke to Mr. Madera. “I have a theory, Mr. Madera. There must be power enough in this system, and far more than enough, to turn the asteroid aside. We don’t need to find out what Zimbardo’s burned out. We should try to get access to the rest of the system. The diagrams I sent you show that there _must_ be plenty of power. We just have to find out how to turn it on!” “That’s sound reasoning, Mark,” nodded Madera. “And probably easier than trying to locate whatever damage Zimbardo did.” For some time, Mark and Madera conversed quietly as Mark flipped through file after file. Diagrams appeared and Mark’s fingers flew over the screen as he pointed out what he had learned while journeying on the _Star Ranger_. Madera nodded, and pointed out several connections Mark had not seen. Once, Madera handed a small diagnostic pack to one of the technicians and sent him to climb the iron latticework. The man returned in a few moments and gave a report. Madera nodded again and turned to Mark. Three hours went by. Joe’s eyes were drooping, but Zip was still intent, his eyes on Mark. Mark clapped his hands and turned to Madera. Madera smiled and raised his eyebrows. With an open hand, he gestured to the control panel. Mark nodded his thanks and pressed several buttons. The files changed rapidly at each new command. Then Mark made fists and clenched a few times as if massaging his fingers. Then he raised his hand and prepared to press a button off to the side of the panel. Suddenly he leaped back a foot, his hands lifted as if he had touched a hot surface. His face was white, his eyes were wide open, and he was breathing hard. His body was trembling as if he were deadly frightened. Zip shot forward, pushing his way through the crowd to reach Mark. “What is it, Mark? What’s wrong?” His voice was urgent.