CHAPTER ONEWillisTHE THIN AIR of Mars was chill but not really cold. Itwas not yet winter in southern latitudes and the daytime tem-perature was usually above freezing.The queer creature standing outside the door of a dome-shaped building was generally manlike in appearance but nohuman being ever had a head like that. A thing like a coxcombjutted out above the skull the eye lenses were wide and star-ing and the front of the face stuck out in a snout. The un-earthly appearance was increased by a pattern of black andyellow tiger stripes covering the entire head.The creature was armed with a pistol-type hand weaponslung at its belt and was carrying crooked in its right arm aball larger than a basketball smaller than a medicine ball. Itmoved the ball to its left arm opened the outer door of thebuilding and stepped inside.Inside was a very small anteroom and an inner door. Assoon as the outer door was closed the air pressure in the ante-room began to rise accompanied by a soft sighing sound. Aloudspeaker over the inner door shouted in a booming bassquotWell Who is it Speak up Speak upquotRobert A. HeinleinThe visitor placed the ball carefully on the floor then withboth hands grasped its ugly face and pushed and lifted it to thetop of its head. Underneath was disclosed the face of anEarth-human boy. quotIts Jim Marlowe Docquot he answered.quotWell come in. Come in Dont stand out there chewingyour nails.quotquotComing.quot When the air pressure in the anteroom