"I'm not at liberty to tell you, Manning," replied Connel. "Though I want to thank you for your quick thinking. How did you happen to discover the bomb?" "I was sighting on Regulus for a position check and Regulus was dead astern, so when I swung the periscope scanner around, I spotted that thing stuck to the fin. I didn't bother to think about it, I just yelled." [Illustration] "Glad you did," nodded Connel and turned to stare at the _Polaris_ again. "Now I'm afraid we'll just have to wait until that bomb goes off." "Isn't there anything we can do?" asked Tom. "Not a blasted thing," replied Connel grimly. "Thank the universe we shut off all power. If that baby had blown while the reactant was feeding into the firing chambers, we'd have wound up a big splash of nothing." "This way," commented Astro sourly, "it'll just blast a hole in the side of the ship." "We might be able to repair that," said Tom hopefully. "There she goes!" shouted Roger. [Illustration] Staring out the windshield, they saw a sudden blinding flash of light appear over the stern section of the _Polaris_, a white-hot blaze of incandescence that made them flinch and crouch back. "By the craters of Luna!" exclaimed Connel. Before their eyes they saw the stabilizer fin melt and curl under the intense heat of the bomb. There was no sound or shock wave in the vacuum of space, but they all shuddered as though an overwhelming force had swept over them. Within seconds the flash was gone and the _Polaris_ was drifting in the cold blackness of space! The only outward damage visible was the twisted stabilizer, but the boys realized that she must be a shambles within. "I guess we'll have to wait a while before we go back aboard. There might be radioactivity around the hull," Roger remarked. "I don't think so," said Tom. "The _Polaris_ was still coasting when we left her. We cut out the drive rockets, but we didn't brake her. She's probably drifted away from the radioactivity already." "Corbett's right," said Connel. "A hot cloud would be a hundred miles away by now." He pressed down on the acceleration lever and the jet boat eased toward the ship. Edging cautiously toward the stern of the spaceship, they saw the blasted section of the fin already cooling in the intense cold of outer space. "Think I'd better call a Solar Guard patrol ship, sir?" asked Roger. "Let's wait until we check the damage, Manning," replied Connel. "Yeah," chimed in Astro grimly, "if I can help it, I'm going to bring the _Polaris_ in." He paused and then added, "If I have to carry her on my back." As soon as a quick check with the radiation counter showed them that the hull was free of radioactivity, Major Connel and the three cadets re-entered the ship.