There was no signature, nor any date. The only noticeable thing about this brief communication was that it was written in yellow pencil of a peculiar shade. Mr. Sabin’s eyes glittered as he read. “The yellow crayon!” he muttered. Duson knocked softly at the door. Mr. Sabin thrust the letter and envelope into his breast coat pocket. CHAPTER II “This is the luggage porter, sir,” Duson announced. “He is prepared to answer any questions.” The man took out his book. Mr. Sabin, who was sitting in an easy-chair, turned sideways towards him. “The Duchess of Souspennier was staying here last week,” he said. “She left, I believe, on Thursday or Friday. Can you tell me whether her baggage went through your hands?” The man set down his hat upon a vacant chair, and turned over the leaves of his book. “Guess I can fix that for you,” he remarked, running his forefinger down one of the pages. “Here we are. The Duchess left on Friday, and we checked her baggage through to Lenox by the New York, New Haven & Hartford.” Mr. Sabin nodded. “Thank you,” he said. “She would probably take a carriage to the station. It will be worth another ten dollars to you if you can find me the man who drove her.” “Well, we ought to manage that for you,” the man remarked encouragingly. “It was one of Steve Hassell’s carriages, I guess, unless the lady took a hansom.” “Very good,” Mr. Sabin said. “See if you can find him. Keep my inquiries entirely to yourself. It will pay you.” “That’s all right,” the man remarked. “Don’t you go to bed for half-an-hour, and I guess you’ll hear from me again.” Duson busied himself in the bed-chamber, Mr. Sabin sat motionless in his easy chair. Soon there came a tap at the door. The porter reappeared ushering in a smart-looking young man, who