For more than an hour he waited, sometimes outside his patient’s door, sometimes by Lucille’s; but nothing happened to alarm him throughout his watch, and he knew the approach to the secret staircase was securely guarded. No intruder could reach Mr. Sivewright’s room that night, at any rate. Lucius went down-stairs at last, and smoked a cigar in the brewhouse while the detective took his round through all the lower rooms. Thus the night wore away, and in the gray dawn Lucius once more mounted the stairs, and paced the corridor. Again all was silence. This time he heard no sigh from Lucille. His heart was relieved by the thought that she was sleeping peacefully. With the dawn—Aurora the rosy-fingered showing poorly at this east-end of London—he made his way back by the garden-wall, the barges, and the wharf, and returned to his own abode, which looked sordid and cheerless enough beneath the pale light of newborn day—cold and dreary and poor, lacking the picturesqueness of a lodge in the primeval forest, and but slightly surpassing it in luxury. He laid himself down and tried his hardest to sleep; but the thought of old Homer Sivewright and his hidden enemy, the domestic poisoner, drove away slumber. ‘I shall sleep no more till I have fathomed this mystery,’ he said to himself wearily. But at last, when the sun was shining through the poor screen afforded by a calico blind, he did fall into a kind of sleep, or rather that feverish condition which is neither sleeping nor waking. From this state he woke with a start—that kind of shock which jars the nerves of the dreamer when his vision ends on the brink of a precipice, whence he feels himself descending to fathomless depths below. His forehead was damp with a nameless horror; he trembled as he rose in his bed. It was as if a voice had spoken in his ear as he slept. ‘What if Lucille were the poisoner?’ Great Heaven! how could so vile a thought shape itself in his mind? Yet with the thought there arose before him, as if it had been shown to him upon the open pages of a book, all those circumstances which might seem to point to this hideous conclusion. Who else, in that lonely old house, had the same power to approach the patient? In whom else would Homer Sivewright trust as blindly? He remembered Lucille’s agitation when he first hinted the possibility of poison—that whitening cheek, that sudden look of horror. Might not guilt look thus? And then her emotion yesterday morning, when she had dropped lifeless at his feet? Could anything _but_ guilt be thus stricken? ‘O God,’ he cried, ‘I am surely going mad! Or how else could such horrible thoughts enter my mind? Do I not know her to be good and pure, loving, unselfish, compassionate? And with the conviction of her goodness firmly rooted in my heart, can I for one moment fear,—ay, even though circumstances should weave a web of proof around her, leaving not one loophole for escape?’