“Gee whiz! there’s nothing to it,” thought Danny. “That fellow was going to the Darling residence. He was alarmed when he saw this car, and he has taken the number of it. He don’t know who owns it, then, so why did he change his mind? He certainly must be off color, or he would not have feared to enter the house. But why--why be hanged! It’s up to me, by gracious, to find out why.” Danny abruptly ended his vain speculations. He quickly wrote the brief note that Nick found a little later, then sprang from the car and started after the departing stranger. Danny discovered him nearly a block away, after rounding the corner--an erect, finely built man, fashionably clad, and having all of the outward indications of a gentleman. He was about thirty years old, with dark eyes and hair and clean-cut features, in many respects a strikingly handsome man. Danny shadowed him to the city. He saw him enter an automobile garage and consult a reference book, one containing the license numbers of New York cars and the names of their owners. His face, when he departed, wore a darker cloud, a look of increasing apprehensions. “Gee! he’s found out that the car belongs to Nick Carter,” Danny readily reasoned. “That don’t seem to please him worth a cent, which shows that my suspicions are all to the good. I’ll not lose sight of him, by gracious, until I learn who he is and where he hangs out.” Danny then shadowed him to a leading hotel, where his quarry spent nearly an hour at lunch in the café, afterward sauntering out and bringing up, ten minutes later, near a large West Side apartment house, then known as the Ashburton Chambers. This house evidently was his destination, for he gazed up at one of the side windows when crossing a street on the corner of which the lofty building stood. “He’s got a date with some one,” thought Danny, watching him from the opposite side of the avenue. “Or mebbe he has a suite there and--no, by ginger, I was right. He’s here to see that woman.” She emerged from a side door of the house just as the man was crossing the street--a finely formed woman in a stylish walking costume, a figure so striking and graceful that Danny at once felt sure that he had seen her before. Her face was partly hidden under a polka-dotted veil, however, precluding immediate recognition. They caught sight of one another at the same moment, and the man stopped on the corner, while the woman hastened to join him. Remaining there, apparently heedless of numerous passing pedestrians, they entered into a subdued and earnest conversation, the gravity of which was obvious. “I’ve got to have a nearer look at her,” thought Danny. “I’m dead sure I’ve seen her before. Mebbe, too, I can get a line on what they are talking about by passing near them.”