Worming their way through the crowd when their prey changed to the Sixth Avenue Elevated, Gene and Paula soon reached points of vantage on either side of the German, who carried his black bag tightly grasped in his right hand, and the trio kept this formation until they reached Fiftieth Street, when the girl apparently started to make her way toward the door. Something caused her to stumble, however, and she pitched forward right into the arms of the German, who by that time had secured a seat and had placed his bag beside him, still guarding it with a protecting arm. Before the foreigner had time to gather his wits, he found himself with a pretty girl literally in his lap--a girl who was manifestly a lady and who blushed to the tips of her ears as she apologized for her awkwardness. Even if the German had been a woman-hater there would have been nothing for him to do but to assist her to her feet, and that, necessarily, required the use of both hands. As it happened, Doctor Albert was distinctly susceptible to feminine charms, and there was something about this girl's smile which was friendly, though embarrassed. So he spent longer than was strictly essential in helping her to the door--she appeared to have turned her ankle--and then returned to his seat only to find that his portfolio was missing! Recriminations and threats were useless. A score of people had left the car and, as the guard heartlessly refused to stop the train before the next station, there was naturally not a trace of the girl or the man who had accompanied her. By that time, in fact, Barlow and Paula had slipped into the shelter of a neighboring hotel lobby and were busy inspecting the contents of Doctor Albert's precious brief case. "Even if there's nothing in it," laughed the girl, "we've had the satisfaction of scaring him to death." Gene said nothing, but pawed through the papers in frantic haste. "A slip of oiled paper," he muttered. "By the Lord Harry! here it is!" and he produced a pencil which his trained fingers told him was lighter than it should be. With a wrench he broke off the metal tip that held the eraser, and from within the wooden spindle removed a tightly wrapped roll of very thin, almost transparent paper, covered with unintelligible lettering. "What's on it?" demanded Paula. "I'll never tell you," was Barlow's reply. "It would take a better man than I am to decipher this," and he read off: "I i i t f b b t t x o...." "Code?" interrupted the girl. "Sure it is--and apparently a peach." The next moment he had slipped the paper carefully into an inside pocket, crammed the rest of the papers back into the brief case, and was disappearing into a phone booth. "Better get down to work, dear," he called over his shoulder. "I'm going to report to the office here and then take this stuff down to Washington!" And that was the last that Paula saw of him for a week.