"We're ... sending most of the stuff to Mars," stammered Fallon. "B-but we're keeping the atom fuel on the ship. It's w-worth a lot. If something happened to most of us ... why ... two men could take the ship back to Earth and land it anywhere they wanted to. And if ... if a person had contacts, that atom fuel would be w-worth a lot. Millions." McCauley was jolted. "Suppose," he said grimly, "that you tell me the rest of your idea." "Why ... why ..." Fallon tried hard to be ingratiating and confidential, but he couldn't make it. So he said harshly: "I'm going to tell you something. My name's Fallon, but I'm not the Fallon you think I am. I've got a brother. He was slated to come on this trip. I was in the pen. I broke out. They were close after me. I went to my brother for money and help. He's tried to help me before, tried to make me stay out of trouble. This time was the worst, but this time he wouldn't help me any more. It was too serious. So I ... slugged him and took his papers and his orders and reported for duty instead of him. I ... I guess he couldn't bring himself to turn me in, but he figured I'd be caught before take-off. But I bluffed it through!" Here a trace of pride came into his voice. "I bluffed it through, and I came on the trip in his place because there wouldn't be anybody hunting me out here." McCauley did not display any feeling at all. That Fallon had committed a crime or crimes back on Earth--forty million miles away--meant nothing here. Not if he did his work. But.... "Well?" said McCauley. "I'm telling you," said Fallon urgently. "You didn't tell the others that I'd lifted their stuff. You had to have a reason. Then Hathaway almost got it when that rocket blew. And Soames came close to frying in a rocket blast. There are too many queer things happening! You not telling the others on me, and then...." McCauley sat perfectly still, staring at Fallon. "It adds up," said Fallon defiantly. "There's millions in atom fuel here. If things happen to the others, you can get back to Earth and land anywhere, and if you've got contacts so you can sell the atom stuff...." McCauley waited ominously. Fallon tried to go on, and could not. But his meaning was clear. In some twisted fashion he had worked out what he believed a logical explanation for McCauley's behavior to him. It implied that McCauley did not see the Mars expedition as a normal man would see it, but as an opportunity for the first space robbery in history and perhaps the most stupendous criminal coup since time began. It was true that the atomic fuel for the Mars reactor had a money value in the tens of millions. To McCauley, that fact would mean that it was something to be guarded and taken care of. But to Fallon, it was something to be stolen. And he thought McCauley saw it the same way. "I suppose," said McCauley evenly, "that you've guessed that I plan to kill off the others and go back to Earth alone. Is that it?" Fallon twitched nervously.