Above the shrill whistle for more coal I heard a voice shout, “Began with an explosion—­it’s the firebug, all right.”  I looked up.  It was McCormick, dripping and grimy, in a high state of excitement, talking to Kennedy.

I had been so busy trying to make myself believe that I was really of some assistance about the engine that I had not taken time to watch the fire itself.  It was now under control.  The sharp and scientific attack had nipped what might have been one of New York’s historic conflagrations.

“Are you game to go inside?” I heard McCormick ask.

For answer Kennedy simply nodded.  As for me, where Craig went I went.

The three of us drove through the scorching door, past twisted masses of iron still glowing dull red in the smoke and steam, while the water hissed and spattered and slopped.  The smoke was still suffocating, and every once in a while we were forced to find air close to the floor and near the wall.  My hands and arms and legs felt like lead, yet on we drove.

Coughing and choking, we followed McCormick to what had been the heart of the fire, the office.  Men with picks and axes and all manner of cunningly devised instruments were hacking and tearing at the walls and woodwork, putting out the last smouldering sparks while a thousand gallons of water were pouring in at various parts of the building where the fire still showed spirit.

There on the floor of the office lay a charred, shapeless, unrecognisable mass.  What was that gruesome odour in the room?  Burned human flesh?  I recoiled from what had once been the form of a woman.

McCormick uttered a cry, and as I turned my eyes away, I saw him holding a wire with the insulation burned off.  He had picked it up from the wreckage of the floor.  It led to a bent and blackened can—­that had once been a can of ether.

My mind worked rapidly, but McCormick blurted out the words before I could form them, “Caught in her own trap at last!”

Kennedy said nothing, but as one of the firemen roughly but reverently covered the remains with a rubber sheet, he stooped down and withdrew from the breast of the woman a long letter-file.  “Come, let us go,” he said.

Back in our apartment again we bathed our racking heads, gargled our parched throats, and washed out our bloodshot eyes, in silence.  The whole adventure, though still fresh and vivid in my mind, seemed unreal, like a dream.  The choking air, the hissing steam, the ghastly object under the tarpaulin—­what did it all mean?  Who was she?  I strove to reason it out, but could find no answer.

It was nearly dawn when the door opened and McCormick came in and dropped wearily into a chair.  “Do you know who that woman was?” he gasped.  “It was Miss Wend herself.”

“Who identified her?” asked Kennedy calmly.

“Oh, several people.  Stacey recognised her at once.  Then Hartstein, the adjuster for the insured, and Lazard, the adjuster for the company, both of whom had had more or less to do with her in connection with settling up for other fires, recognised her.  She was a very clever woman, was Miss Wend, and a very important cog in the Stacey enterprises.  And to think she was the firebug, after all.  I can hardly believe it.”