The Brown Robin arose, apparently much pleased with the success of her visit, and shortly after left. Nick went back to Edith, telling her to prepare herself for her walk and saying that he wanted to go in the neighborhood of the Festus Club, for a moment’s word with one of his clients. When she came back, ready for her walk, she asked: “Who was your caller, Nick?” “The Brown Robin.” “Nick! You don’t mean that that pretty woman is the Brown Robin?” “No doubt of it!” “How do you know?” “I called on the Brown Robin to-day, disguised as Alpheus Cary.” “And she had the audacity to come and see you, knowing you are retained to expose her?” “Boldness and audacity are her weapons.” “What did she want?” “She pretended that she was a Mrs. Ansel, who was being blackmailed by the Brown Robin.” “She came to measure you, Nick, to size you up, as you call it.” “Perhaps that was her game. She has never seen me, I suppose. But, Edith, I think she was laying the trap of which I spoke this morning.” “How?” “She wanted me to accompany her as Mrs. Ansel to meet the Brown Robin and compel the giving up of the letters.” “Ah! and you do not walk into the trap.” “But I will. Something of value may come out of it. I will escape it, never fear. Chick and Patsy will not be far off, I can tell you.” Edith made no reply. Quite evidently she did not like it, but she knew it was useless to combat Nick when he had made up his mind. So she held her peace and went out for her walk with him. During their walk they stopped at the door of the Festus Club, where Nick told Mr. Cary that he had his case so well in hand that the old gentleman could go home and sleep in comfort. CHAPTER VII. CHICK’S GREAT DISCOVERY. When Nick had left Chick and Patsy at the hotel, where he had taken off the disguise of Mr. Cary, the two young detectives discussed their own details for the night. “We’re to keep a watch over Mountain,” said Chick. “He seems able to watch over himself,” replied Patsy. “Oh, he’s able enough,” said Chick. “It isn’t that. The chief wants to know the moment he gets the word from the Brown Robin. He believes that the Brown Robin will show up to-night.” “Then we must be on,” said Patsy. “It’s up to us to decorate the lobby of the Empire with our beauty. Say, Chick, it’s the old story. We’ve swung about the Tenderloin so much lately that too many know us.” “And we’ll have to look different. Well, Patsy, let’s swing out as swell Willie boys.” Patsy laughed heartily, pounding the pillar against which he had been leaning. “A sweet Willie boy you’ll make Chick,” he said, after a while, “with those broad shoulders of yours. No, no, Chick. Do your own act. Swing out as a regular swell.” Chick looked at his watch, and said: