Whatever he was going to add was lost in a sudden, rending concussion that flung them violently down, and plunged the room into darkness. * * * * * Staggering to his feet a moment later, bruised and shaken, Stoddard gasped out: "Professor are you there? Are you all right?" A groan answered him, and for a moment his heart sank, but then came the reassuring call: "Yes--all right, I guess. And you?" "O.K. Let's get out of here, quick!" An ominous hissing sound beat on their ears, as they groped their way toward the door. Evidently escaping gases from the deranged mechanism, thought Stoddard. The floor rose at an angle, indicating that the rocket was half over on its side. They found the door, and struggled along the twisted corridor toward a flight of stairs that would lead below; found it, descended, and groped along another dark corridor, seeking an exit; when suddenly, around a bend, daylight confronted them, and to their joy they saw that one of the main doors had been burst open by the impact. Approaching it, they peered out--to be greeted by an awed group of officials and mechanics from the field. As they climbed through, dropped to the ground, the group retreated, taking no chances. "Back!" called Professor Prescott, warning and reassuring them with a word. Then, turning to his companion: "Come on, Jack--run! This thing is likely to explode at any moment." Following this advice, Stoddard raced from the rocket with the rest. At a safe distance, he turned and peered back--to see it standing there at a crazy angle, dust and fumes issuing from under it in a blast that was hollowing a deep crater to the far side. Even as they looked, the strange craft quivered, tottered, and fell over on its side, and the next instant was enveloped in a blinding sheet of flame that brought with it a dull detonation and a blast of dazing heat. The party backed still farther away. "A nasty mixture, oxygen and hydrogen," muttered the professor, feeling of his singed eyebrows. "We got out of there just in time, Jack." "I'll say we did!" Stoddard agreed, with a shudder. * * * * * By now the higher officials of the field were on the scene, among them a number of Army men. Curiosity ran high, not unmingled with indignation. Who were these strange visitors? Where had they come from? What did they mean by endangering the lives of everyone, with their damned contraption? Inquiring for the commandant, they were taken to him--Major Clark Hendricks, U.S.A.--and Stoddard briefly outlined their astounding story, producing credentials, whereupon a squadron of fast military planes was assembled.