"Experimental missile, hell!" snorted Jonner, comprehension dawning. "Qoqol, what would have happened if we hadn't shifted orbit to take aboard that G-boat?" Qoqol calculated a moment. "Hit our engines," he announced. "Dead center." Jonner's blue eyes clouded ominously. "Looks like they're playing for keeps this time, boys." * * * * * The brotherhood of spacemen is an exclusive club. Any captain, astrogator or engineer is likely to be well known to his colleagues, either personally or by reputation. The ship's doctor-psychologist is in a different category. Most of them sign on for a few runs for the adventure of it, as a means of getting back and forth between planets without paying the high cost of passage or to pick up even more money than they can get from lucrative planetbound practice. Jonner did not know Serj, the _Radiant Hope_'s doctor. Neither T'an nor Qoqol ever had heard of him. But Serj appeared to know his business well enough, and was friendly enough. It was Serj's first trip and he was very interested in the way the ship operated. He nosed into every corner of it and asked a hundred questions a day. "You're as inquisitive as a cadet spaceman, Serj," Jonner told him on the twenty-fifth day out. Everybody knew everyone else well by then, which meant that Jonner and Qoqol, who had served together before, had become acquainted with T'an and Serj. "There's a lot to see and learn about space, Captain," said Serj. He was a young fellow, with fair hair and an easy grin. "Think I could go outside?" "If you keep a lifeline hooked on. The suits have magnetic shoes to hold you to the hull of the ship, but you can lose your footing." "Thanks," said Serj. He touched his hand to his forehead and left the control deck. Jonner, near the end of his eight-hour duty shift, watched the dials. The red light showing the inner airlock door was open blinked on. It blinked off, then the outer airlock indicator went on, and off. A shadow fell across Jonner briefly. He glanced at the port and reached for the microphone. "Careful and don't step on any of the ports," he warned Serj. "The magnetic soles won't hold on them." "I'll be careful, sir," answered Serj. No one but a veteran spaceman would have noticed the faint quiver that ran through the ship, but Jonner felt it. Automatically, he swung his control chair and his eyes swept the bank of dials. At first he saw nothing. The outer lock light blinked on and off, then the inner lock indicator. That was Serj coming back inside. Then Jonner noted that the hand on one dial rested on zero. Above the dial was the word: "ACCELERATION." His eyes snapped to the radio controls. The atomic pile levers were still at their proper calibration. The dials above them said the engines were working properly. The atomic tug was still accelerating, but passengers and cargo were in free fall. Swearing Jonner jerked at the levers to pull out the piles aboard the tug.