All at once it dawned upon him that the seat next to him was empty. "Alice, Alice," he muttered, trying to shake off his stupor, "Alice, where are you?" There was no reply. The driver, his hands on the steering disc, was slumped forward in his seat, his head sunk on his breast. With a stupendous effort Ralph managed to open the glass window in front of him. Instantly the strong odor of chloroformal almost overpowered him, and a terrible sensation of nausea forced him to cling blindly to his seat. In a moment it passed and he was able to collect his senses somewhat. His first thought was for Alice. His dimmed sight had cleared sufficiently for him to see that she was not in the cab. He thought she must have fallen into the sea, and in his agony he cried aloud her name again and again. And then a recollection came to him, of her father's words on the first morning of their visit. He had feared for Alice. Someone had threatened her. Ralph forced his still wandering mind to concentrate. Some one had threatened to kidnap her, and that someone was Fernand 60O 10. He recalled the stranded aerocab. Its helplessness had been a trick to deceive him, and to get near enough to drug him and his driver while they took Alice away. The thought aroused him from his dreadful lethargy. With a rush his vitality came back. He flung himself upon the stupefied driver and shook him violently. The cab was still flying at an even speed in a great circle and Ralph saw that it was imperative that he get control of it at once, for another machine, bound evidently for New York, was bearing down upon the helpless men. With a powerful shove he got the driver into the auxiliary seat and climbed over, seizing, as he did so, the steering disc. He flung it over, just in time to escape the onrushing cab, whose occupants, as it passed, leaned out, and in fluent profanity inquired if he wanted the whole airway. Unheeding, Ralph set the steering disc toward New York, and proceeded to lighten the cab. Overboard went the glass doors, cushions, matting, even the hood of the machine. Everything that he could wrench off he tossed to the dark waters beneath him. The cab, relieved of the weight of its equipment shot ahead at tremendous speed, and in less than ten minutes dropped onto the landing place on top of the scientist's laboratory. Leaving the driver where he was Ralph dashed into the building. Meeting Peter he did not stop, only motioned him to the cab while he himself sprang to the nearest Telephot. And within fifteen minutes every detective and special agent had been notified of the disappearance of Alice. Ralph had immediately transmitted the lost girl's photograph to the Central Office where it was placed before a Telephot connecting with every member of the entire police force, and the picture was reproduced for them in their portable radio instruments for ten seconds, enabling them to get her features firmly impressed on their minds.