A tragedy had been enacted, which the flames concealed and the only clew which the Bradys had secured was the delicate lady’s handkerchief. This alone could furnish the only suggestion to be gained in any way from the affair. Whether it would prove a sufficient means for the complete revelation of the mystery or not, remained to be seen. The detectives hoped it would. CHAPTER II. FOLLOWING THE CLEWS. Fire had destroyed all tangible evidence of the supposed murder. The Bradys were up against a hard proposition. To evolve the truth from the matter as it now stood did not by any means seem easy. Insurmountable difficulties had seemed to present themselves. All hung upon the single clew. This was the lace handkerchief. It was of delicate workmanship and had certainly belonged to a lady of refinement. All manner of deductions could be made. It might be assumed that the victim was a wealthy woman, decoyed into a trap of death and for some unknown purpose murdered. The Bradys pondered over the case long and deeply. The ruins of the fire were visited. An inspection seemed to verify the fact of the murder. In the ashes there were found the bones of an unknown victim. So nearly consumed were they that it was not easy to say whether they were those of a man or a woman. But it was safe to assume the latter. But beyond this, all was a wall of mystery. The detectives learned that the inmates of the tenement were an Irish family by the name of Roche. They were honest working people and had been absent for the night on a visit to an adjoining town. It was easily proved that they had no connection whatever with the crime. Thus matters remained in statu quo when one day the detectives dropped into the office of the Chief of the Secret Service. “Hello, boys!” called out the chief, in his cheery way. “What is the good word to-day?” “We are up a stump,” replied Old King Brady. “How so?” “You know that mysterious Fifteenth street fire and murder?” “Yes.” “We can’t get a clew beyond this lace handkerchief.” “Indeed!” exclaimed the chief. “Well, that is something. Let me see the handkerchief.” Old King Brady placed a hand in his pocket for the handkerchief. To his surprise it was not there. “Oh, I recall,” he said, “I left that handkerchief in the room at our lodging house. Do you remember, Harry?” “Yes,” replied the young detective. “That is the truth.” “Then that is your only clew?” asked the chief. “Yes.” “To be sure it is a slight one. Was it a lady’s handkerchief?” “Yes.” “Then the victim was a woman?” “We think so.” The chief was silent a moment. “Many a dark crime has been covered up in that same way,” he said. “Nothing obliterates the traces of a crime like fire.” “That is right,” agreed Old King Brady. “The oddest thing of all is that the house was occupied by people who could have had no possible connection with the crime on account of absence.”