"No, it isn't!" cried Dick. "I'm not going to give up yet! We can still make time when we get the repairs made, and I'll run the motor until her bearings melt before I give up!" "That's the way to talk!" cried the army man. "And we're all with you. There's a good chance yet, for those fellows must be desperate, or they'd never have tried what they did. My opinion is that they hope to reach San Francisco in a last dash, and they were afraid we'd come in ahead of them. But I can't understand how that army man aboard would permit such a thing. It is past belief!" It was no easy task to make the repairs with the airship in motion. Spare parts, including a sprocket chain, were carried aboard, but the work had to be done close to the other revolving propeller, and, as slowly as it was whirling about, it went fast enough to cause instant death to whoever was hit by it. So extreme caution had to be used. To add to the troubles it began to rain violently, and a thunderstorm developed, which made matters worse. Out in the pelting storm, with electrically-charged clouds all about them, and vivid streaks of lightning hissing near them, the aviators worked. They were drenched to the skin. Their hands were bruised and cut by slipping wrenches and hammers. Their faces were covered with black grease, dirt and oil. But still they labored on. The storm grew worse, and it was all the Abaris could do to stagger ahead, handicapped as she was by half power. But there were valiant hearts aboard her, and everyone was imbued with indomitable courage. "We're going to do it!" Dick cried, fiercely, and the others echoed his words. Finally, after many hours of work, the last rivet was driven home, and Mr. Vardon cried: "There we are! Now then, full speed ahead!" The repaired propeller was thrown into gear. It meshed perfectly, and once more the Abaris shot ahead under her full power. "Speed her up!" cried Dick, and the motor was put to the limit. But much precious time had been lost. Could they win under such adverse circumstances? It was a question each one asked himself. Darkness came on, and the tired and weary aviators ate and slept. The night passed, a clear, calm night, for the storm had blown itself out. High over the mountains soared the airship through the hours of darkness. She was fighting to recover what she had lost. And when morning came they calculated they were but a few hundred miles from San Francisco. Paul, who had gone to the pilot-house to relieve Innis, gave a startled cry. "Look! Look!" he shouted. "There's the other airship!" And as the others looked they saw, ahead of them, emerging from the midst of a cloud, Uncle Ezra's speedy craft. And, as they looked, they saw something else--something that filled them with horror.