It was a serious matter because of its implications rather than the facts themselves. The First Martian Expedition needed everything its members could give it for the safety of them all. If somebody considered himself apart from the rest, if one member of the crew was willing to injure the others by stealing from them, the situation was very, very bad. In fact, having a thief among the six was like a serious accident occurring to the Expedition's equipment. It would be comparable to a vital defect in the miniature atom-pile which was to supply energy for them to live by when they reached Mars' surface. In a sense, though, the Expedition itself was the result of an accident of a different sort. The first part of this coincidence was the fact that some two years earlier the asteroid Eros had passed close to Earth on its elongated elliptical orbit around the sun. Eros is one of those rock and metal fragments which are found most often in orbits between Mars and Jupiter. Some people maintain that they are fragments of a planet which exploded some hundreds of millions of years ago, and there is some evidence to back this view. For one thing, some circle the sun in extremely eccentric paths. Eros swings out at its farthest between Mars and Jupiter, but when nearest the sun it dives in between Earth and Venus. Sometimes--rarely--it comes close to Earth in its passage across Earth's orbit. This had happened two years ago. The second part of the coincidence was the purely fortuitous fact that only two Earth-years later Eros would pass even closer to the planet Mars. The two accidents added up to an opportunity, when McCauley added rockets and other resources of the Space Service. And the Service seized it. So two years ago Colonel Ed McCauley had landed a ship on the asteroid, then close to Earth. He'd led a work crew which drove drill holes into the asteroid's solid metal substance. They made anchorages to fasten supplies to, and McCauley'd anchored the supplies. Then he took his ship back to Earth. On the way he'd passed other ships going out to Eros. They also anchored supplies on it. In one hectic month, the Space Service unloaded on the tiny asteroid all the supplies and equipment--some two hundred-odd tons of it--that the First Martian Expedition would need not only on Mars, but in getting back from Mars, which was equally important. Then the Space Service waited.