He believed that it was confined to a point in the rear of the tenement and had, as yet, not extended beyond one room. Each of the detectives carried a dark-lantern. It could hardly furnish light enough to penetrate the pall of stifling smoke, but yet enabled them to find their way up the stairs. Choking and gasping they made their way bravely from room to room. The dwelling was humbly furnished. It was plainly the abode of people of small means. It was dingy and meagre. The Bradys looked for a clew to the supposed crime. Suddenly Harry went down on his knees and focused his lantern on the floor. He cried excitedly: “Ah, here is the clew!” A trail of blood marked the floor. In the trail lay a white handkerchief of dainty texture. The detectives examined it closely. Harry gave an exclamation. On one corner in ink was marked a name: “Evelyn Grimm.” This was the name. It was a clew. The detectives realized this. At once they began to follow the trail of blood. They felt certain of a sure revelation of the mystery. The blood trail led to the door of a room at the end of the corridor. This door was closed and locked. What was beyond it, the detectives could only guess. But in their mind’s-eye they saw the mangled remains of the murderer’s victim. So they threw themselves against the door. And beneath their combined weight it gave way. As it crashed in, however, they were met by an impassable barrier. Flames and smoke filled the doorway and forbade their entrance. They were driven back. In fact it now became a question of self-preservation. The old building was like a tinder-box. The Bradys seemed to be literally penned in by the fire and smoke. There was no time to lose. “No use, Harry!” cried Old King Brady. “We are beaten for just now. We must get out of here.” The detectives reached the stairs. But escape in this direction was cut off. Flames were in their faces. At the other end of the corridor was a window opening upon the street. The detectives made a rush for this. They reached it just as the sash was carried away by a stream of water from the firemen’s hose. This gave the detectives a chance. Drawing a deep breath of fresh air they felt returning strength. Harry vaulted lightly over the sill. It was fifteen feet to the area below. The firemen shouted, but Harry dropped to the flagging. Old King Brady followed. In another moment they were safe within the fire lines. By this time a great crowd was in the street, attracted in spite of the driving storm. The firemen were badly handicapped by the snow, but yet fought their way bravely while the rickety tenement was being consumed. The fire was not allowed to spread, but the tenement was reduced to ashes. Then the crowd dispersed. The detectives left the scene and returned to their lodgings for the night. One thing was certain.