The doors that separated me from Doddridge Knapp's room were shut and locked. What was behind them? I wondered. Was there anything in Doddridge Knapp's room that bore on the mystery of the hidden boy, or would give the clue to the murder of Henry Wilton? As I gazed on the panels the questions became more and more insistent. Was it not my duty to find the answer? The task brought my mind to revolt. Yet the thought grew on me that it was necessary to my task. If vengeance was to be mine; if Doddridge Knapp was to pay the penalty of the gallows for the death of Henry Wilton, it must be by the evidence that I should wrest from him and his tools. I must not stop at rummaging papers, nor at listening at keyholes. I had just this morning secured the key that would fit the first door. I had taken the impression of the lock and had it made without definite purpose, but now I was ready to act. With a sinking heart but a clear head I put the key cautiously to the lock and gently turned it. The key fitted perfectly, and the bolt flew back as it made the circle. I opened the door into the middle room. The second door, as I expected, was closed. Would the same key fit the second lock, or must I wait to have another made? I advanced to the second door and was about to try the key when a sound from behind it turned my blood to water. Beyond that door, from the room I had supposed to be empty, I heard a groan. I stood as if petrified, and, in the broad daylight that streamed in at the window, with the noise and rush of Clay Street ringing in my ears, I felt my hair rise as though I had come on a ghost. I listened a minute or more, but heard nothing. “Nonsense!” I thought to myself; “it was a trick of the imagination.” I raised my hand once more to the lock, when the sound broke again, louder, unmistakable. It was the voice of one in distress of body or mind. What was it? Could it be some prisoner of Doddridge Knapp's, brought hither by the desperate band that owned him as employer? Was it a man whom I might succor? Or was it Doddridge Knapp himself, overwhelmed by recollection and remorse, doing penance in solitude for the villainy he had done and dared not confess? I listened with all my ears. Then there came through the door the low, stern tones of a man's voice speaking earnestly, pleadingly, threateningly, but in a suppressed monotone. Then the groan broke forth again, and it was followed by sobs and choked sounds, as of one who protested, yet, strangely, the voice was the same. There was one man, not two. It was self-accusation, self-excuse, and the sobs seemed to come in answer to self-reproaches.