“Bart Bailey’s presence in New York, and what occurred to-day.” “What do you see in that?” “I am convinced that Bailey was in league with the other crooks when he stole the diamond sunburst, and it’s a hundred to one that he still is in league with them in some capacity,” Nick explained. “If he had not been stealing the jewel, it probably would have gone the way of the other plunder. The circumstances forced him to bolt with it, however, and to lie low ever since.” “But how can we take advantage of all that?” asked Chick. “I don’t quite get you.” “We’ll take advantage of his antipathy for his half sister,” said Nick. “He don’t like her, despite their kinship, and he already has repeatedly threatened her.” “But how take advantage of it?” “He will hear of what occurred to-day; that she made no intentional move to prevent the police from getting him, despite that she could easily have done so,” said Nick. “Take it from me, Chick, he’ll get after her for that. He will hate her more than before, the knavish rat, and may go even so far as to attempt violence. By keeping an eye on her, therefore, we not only may protect her, but also pick up Bart Bailey himself. Then, if he still is in league with the department-store thieves, we perhaps may trail him to the lair of the entire gang.” “By Jove, that’s no wild-and-weird fancy,” Chick now declared, with some enthusiasm. “That realty looks good to me, Nick.” “That being the case. Chick, you had better tackle that string to our bow,” Nick directed. “Pack a grip with what you may need for a few days, and go in disguise to the Lexington Avenue house in which Helen Bailey is boarding.” “To remain there?” “Yes, temporarily. Engage a room and board, if possible, and you then will have the girl right under your eye. Reveal nothing to her, however. That might queer an opportunity to pick up her brother.” “Trust me to have foreseen that,” Chick replied, rising. “I’ll be ready to leave in ten minutes, and will phone you to-morrow morning.” “Good enough,” Nick said approvingly. “A reference may be required by the landlady. Take the name of Fred Lamont, and say you are a nephew of Mr. Calvin Page, cashier of the Trinity Trust Company. I will presently telephone to Page and inform him of the situation. He will assure the landlady, in case she rings him up.” “I’ve got you,” Chick nodded, turning to go. “I will have decided by to-morrow how Patsy and I can best begin operations,” Nick added. “I think we’ll take a look at the store, for a starter, and at a few of its nine hundred clerks.” “We may pick the crooks from the nine hundred merely by their looks,” laughed Patsy. “That would be going some, chief, for fair.” CHAPTER IV. PICKING UP A TRAIL.