“I want to make a test landing and see how long it takes to unclamp the car and fasten it to the other plane,” said Tom, before he would permit himself to exult. This test was successfully met, and up rose the second plane, carrying the car, just as if the scene had taken place on the field in Chicago, the end of the first lap of the proposed airline express. Not until then did Tom permit himself to see visions of complete success. But after another landing had been made and when the car had been rolled to the third plane, it was evident that the scheme could be carried out. The third plane did not go up, not being quite ready. “Of course,” Tom said to his friends when they were talking it over, “this doesn’t mean that we can make the time which I hope is possible—sixteen hours from coast to coast—but I’m going to make a big effort for those figures.” In the next few weeks matters were rushed to completion. A landing field was secured on Long Island, another in Chicago, one on the outskirts of Denver, and the last one at the Golden Gate. The route was mapped out with care, and guide posts and signal towers were placed in position. Then, on a certain day, after many exhaustive tests, it was decided to inaugurate the first schedule of the airline express. The two planes had been sent, one to Chicago and the other to Denver, while the third was waiting on the Long Island field, where the passenger car had been taken. Newspaper reporters, cameramen, moving picture operators, and many spectators were on hand. “All aboard!” cried Tom, as he gave the signal to start. As he was about to close the door of the car, which would soon be soaring aloft, a boy ran across the field and thrust into the hands of the young inventor a piece of paper. “What is it?” demanded Tom. “Message for you! Man gave me a dollar to deliver it just as you started,” panted the boy. Then, before he could answer, though he had an ominous feeling, Tom felt the car being lifted off the ground. The airline express had started! CHAPTER XVIII CHICAGO Strange and mingled were the feelings Tom Swift had as his great experiment was started. There was exultation mingled with apprehension. Exultation that he had at last triumphed over many difficulties and the plots of his enemies and had reached the point of starting the service which might revolutionize travel. Apprehension lest he might fail, and also apprehension over this latest happening—the giving to him of this note. It had a sinister appearance—this hasty message delivered in such a manner. It was in keeping with some other things that had happened of late. But Tom’s chief concern now was to see that his new craft got safely into the air and on its way. He could deal later with those who sought to steal from him the fruits of his labor and his brain.