Both crawled through the scuttle and picked their way down the steep ladder, and five minutes later found them again in the Strickland apartment. The elderly German still was moaning over the loss of his costly treasures. He looked up with anxious eyes when the detectives entered, saying quickly: “Don’t keep me in suspense. What have you learned, Mr. Carter?” Nick smiled faintly and shook his head. “You must not expect too much of us, Mr. Strickland,” he replied kindly. “Such problems as this are not solved in a moment. Most of our discoveries thus far are of a negative character.” “The police----” “Could not possibly accomplish more than we,” Nick interrupted. “Immediate publicity, too, might result in a disadvantage. You must leave the case entirely to me and wait patiently until morning. We will return at an early hour to continue our work.” “I shall remain here with uncle to-night, Arthur,” said Wilhelmina, turning to her lover. “That will be wise, Mina, I think,” Gordon readily agreed. “But I will return to see you in the morning, Nick.” “Very good,” nodded the detective. “You may expect us about seven o’clock.” CHAPTER III. THE FACE OF A CROOK. “There are only six hundred Stradivarius violins known to be in existence. Their value varies from three to ten thousand dollars, but in a few cases these figures are greatly exceeded. Two are said to be worth no less than fifty thousand dollars each. One is the famous Emperor Stradivarius. It is two hundred years old, and the only one comparable with it is that left by Paganini to the city of Genoa. A sum running into five figures sterling was offered for it.” “Gee! That sure is some fiddle, chief,” declared Patsy Garvan sententiously. Nick Carter was having an early breakfast with Chick and his junior assistant before returning to the Strickland apartment on the morning following the robbery. They had nearly finished, when Nick, after a general discussion of the crime, made the foregoing comments concerning that rare make of violin that had been stolen from the elderly German. “Some fiddle, Patsy, is right,” Chick agreed, laughing over his coffee. “All Strads are very valuable, and many have had a strange and eventful history. Some have been repeatedly stolen, and at times have passed from one uninformed person to another at ridiculously low prices. I recall that one was accepted by a Geneva blacksmith from a traveler who had not money enough to pay for shoeing his horse. It hung for years on a wall in the blacksmith’s house, till a collector of violins happened to see and purchase it. Upon cleaning off the dirt and grime he found the Strad mark on it. He had acquired for a paltry sum an instrument worth thousands of dollars.” “That was tough luck for the poor blacksmith, chief.” “Not at all,” said Nick. “For the violin collector was as square as a brick. He returned and paid the blacksmith all that the instrument was worth.”