"Of course, I know it perfectly. I won't bore you with technical explanations, but on the back of the stretcher is the address of the American art dealer from whom the original canvas was purchased. That should be enough." It was as Indiman said; each of the canvas stretchers carried a small gummed label, the address of a Fulton Street art-supply shop. "That settles the question," remarked the chief of detectives. "I may say finally that I have this cable from the Minister of Police at St. Petersburg, communicated to me through the Russian Consul-General: "'Lely portrait recovered and replaced in the gallery at the Hermitage. Withdraw published reward. "'(Signed) SOBRIESKA.' "A queer piece of business; but this appears to be the end of it," commented the chief. "Needless to say, gentlemen, that you are at liberty to depart. My apologies for the annoyance to which you have been subjected." We all bowed and withdrew to the anteroom. Blake, blushing redly, came up to Indiman; he began to apologize, stuttering pitiably, but Indiman cut him short. "Call up the coach and offer the driver extra fare for the best time his horses can make to this address." He scribbled the name of the street and the house number on a leaf torn from his note-book and handed it to Blake. "Yes, you can come along if you like; it may be the big thing yet." As the carriage rolled along Indiman vouchsafed certain explanations. "As I have already told you," he began, "I bought the picture from a small dealer in the Bowery. I happened to notice it in his window, and, the 'Red Duchess' being one of the half-dozen superlative portraits of the world, I was naturally interested. It was certainly a fine copy, and I was pleased to get it so cheaply. "Now there were two or three circumstances connected with my find that afterwards struck me as peculiar. In the first place it is well known that permission to copy any of the pictures at the Hermitage Gallery is very rarely given, and the authorities are particularly averse to having reproductions made of the Lely portrait. Secondly, why were the edges of the canvas so curiously serrated, giving the picture the look of having been hastily cut away from its frame? And, finally, where and when had this copy been made? for the label of the Fulton Street art dealer on the back bore the date 1903, and this was the 2d of February in the same year. Obviously impossible that the artist could have gone to Russia, painted the picture, and returned with it to New York in a little over a month. "Two days later I was walking up Fourth Avenue, through the district affected by the curio and old-furniture dealers, and I discovered a replica of my 'Red Duchess' hanging in a shop-window. In every respect identical, you understand, the two pictures were unquestionably the work of the same hand. Whose hand?