Capt. Welsh was on his bi-weekly mail run to Luna, the Moon, and for the first time in ten years of service he had a passenger—his own twelve-year-old son. At last Jerry felt a hard jolt under him. He knew the rocket’s tail fins had finally touched ground. Jerry unstrapped himself with rubbery fingers and sat up. Then he tried to stand, but flopped down again. “Wow, I feel giddy!” he groaned. His father laughed. “You’ll get your bearings presently, Son.” How long Jerry had waited to make this space mail run with his father! Then finally last year, Capt. Welsh had said that Jerry could go with him when he became twelve, as he was especially husky and strong for his age. But now that the great moment had come at last, Jerry wasn’t sure he was enjoying it as he had expected, for he had found space so vast, so dark, and so frightening. “Do you still want to be a spaceman, Jerry?” his dad asked suddenly, as though Jerry had spoken his thoughts aloud. “I—I think so, Dad,” he replied hesitantly. “I see you’re doubtful, Jerry,” Capt. Welsh said. “I won’t put you on the spot so early.” They climbed into space gear—electrically-heated suits and clear plastic helmets fitted with radios. Lastly they donned oxygen tanks and flooded their suits with the life-sustaining gas. They gathered up the mail sacks and climbed down the ladder to the ground, heading for the largest of a group of buildings which made up Moonhaven, center of Earthmen’s activity on the airless planet. The stars burned fantastically bright overhead. Traces of frost topped the distant Lunar Alps. It was incredibly cold out here, for the Moon was in its two-week period of night. Capt. Welsh got a receipt for the largest mail bag, and then he and Jerry went out a rear door of the building carrying the rest. An atom-powered mail car awaited them. It had an open top and huge wheels that looked like saw-toothed gears. “Climb aboard the Moon jeep, Jerry,” his father said. “We’ve got ten mail deliveries to make.” Inside, Capt. Welsh pulled down a section of the dash panel revealing a map. “Here’s a map of our route. There aren’t many mail stops on the Moon yet, but they are all important.” “And the mail must go through!” Jerry added. Capt. Welsh nodded soberly. “That’s the first law, Jerry.” As they moved off Jerry saw the big friendly globe of Earth hanging like a green jewel halfway up the jet black sky. He wondered what his mother and baby sister were doing this moment a quarter of a million miles away. Capt. Welsh showed Jerry how to run the jeep. Jerry found this easy for he had already had a course in mechanics in preparation for his future career as a space man. But sometime later their peaceful ride was interrupted when Capt. Welsh suddenly leaned over and grabbed the wheel. Jerry was thrown to the side as the car swerved. The vehicle straightened out and slammed to a halt as his father controlled the wheel and applied the brakes.