Absorbed in his thoughts he walked on past the strip of fence in front of the cottage a few paces down the street, without observing that he was directly before the tall, imposing gray stone mansion known as Delaney House. It stood well back among its leafless trees and ghost-like evergreen shrubberies and cedars that showed like sober-suited sentinels in the cold, white light of the moon. The house looked gloomy enough with its closed doors and heavily shuttered windows from whence no friendly light streamed forth to cheer the weary passer-by, but Mr. Lane did not notice it as he walked slowly past absorbed in his own vexing thoughts. Absorbing as they were they were doomed to have a sudden and startling interruption. The night had been intensely still save for the low whisperings of the winter wind as it swept past in restless sighs, but suddenly its calm was broken by a long, low wail that broke shudderingly upon the silence and repose of the hour, and swelled high and still higher until it became a fearful shriek of mad rage and impotent anger most terrible to hear: “Ah--h--h! Ah--h--h!” That loud, terrible, prolonged shriek fell suddenly and startlingly upon the ears of the detective. He sprung backward with a smothered cry and stared upward to where the sound seemed to issue forth. His eyes fell upon the dark, silent façade of Delaney House. “Ah!” he breathed, and like a horrible echo came that fearful shriek again. “Ah--h--h! Ah--h--h! Ah--h--h!” It seemed to float over his head and die away in the wandering breeze. Again he glanced up at the dark lowering front of Delaney House. This time its darkness was illumined by a line of light that glanced momentarily through the shutters, then abruptly disappeared. CHAPTER XXXII. He stood silently gazing at the windows where the light had so strangely flickered and disappeared with almost the swiftness of a flash of lightning. He was full of wonder over what he had heard and seen. “What a horrible voice!” he said to himself. “It was neither that of a man nor woman, and yet it sounded distinctly human. What was it? I have heard such shrieks within the walls of madhouses, nowhere else. Can it be that some unfortunate lunatic is confined in Delaney House?” He stood still, listening and watching some time, but he neither saw nor heard anything more. The mansion had returned to its usual gloom and silence. It almost seemed to him as if those fearful shrieks and that swift flash of light had been the figment of his own disordered imagination.