And why had each Martian rocket carried the same load each time? Could there be some significance in those Martian lily seeds? Some hidden meaning the Earth had failed to grasp? Some meaning that the things from Mars hoped would be read with each new rocket-load? Why hadn't the Martians come themselves? If they could shoot automatic rockets across the miles of space, certainly they could navigate rockets carrying themselves. The Martian rockets had been closely studied back on Earth but had yielded no secrets. The fuel always was exhausted. More than likely the Martians knew, to the last drop, how much was needed. The construction was not unlike Earth rockets, but fashioned of a steel that was hardened and toughened beyond anything Earth could produce. So for ten years Earthmen had worked unaided to cross the bridge of space, launching ships from the Earth's most favored take-off point, from the top of Mt. Kenya, heading out eastward into space, taking advantage of the mountain's three mile height, the Earth's rotation speed of 500 yards per second at the equator. Scott reviewed his flight, checked the clocklike routine he had followed. Blast-off from Earth. Landing in the drear, desolate Mare Serenitatis on the Moon, refueling the ship from the buried storage tanks, using the caterpillar tractor from the underground garage to haul the rocket onto the great turn-table cradle. Setting the cradle at the correct angle and direction, blasting off again at the precise second, carrying a full load of fuel, something impossible to do and still take off from Earth. Taking advantage of the Moon's lower gravity, its lack of atmosphere. Using the Moon as a stepping stone to outer space. Now he was headed for Mars. If he landed there safely, he could spend two days, no more, no less, before he blasted off for Earth again. But probably he wouldn't reach Mars. Probably he and Jimmy Baldwin, in the end, would be just a few more bones to pave the road to Mars. III A gigantic building, rising to several hundred feet in height, domed, without door or window, stood lonely in the vastness of the red plain that stretched to the far-off black horizon. The building and nothing more. No other single sign of habitation. No other evidence of intelligent life. The Martian lilies were everywhere, great fields of them, bright scarlet against the redness of the sand. But in its native soil the Martian lily was a sorry thing, a poor apology for the kind of flower that grew on Earth. Stunted, low-growing, with smaller and less brilliant flowers. The sand gritted under Scott's boots as he took a slow step forward. So this was Mars! Here, at the North pole ... the single building ... the only evidence of intelligence on the entire planet. As the ship had circled the planet, cutting down its tremendous speed, he had studied the surface in the telescopic glass and this building had been the only habitation he had seen.