One thing troubled him, and that was the existence of the secret staircase, communicating in some manner—which he had been up to this point unable to discover—with Mr. Sivewright’s bedroom. He had sounded Homer Sivewright cautiously upon this subject, and the old man’s answers had led him to believe that he, so long a tenant of the house, knew absolutely nothing of the hidden staircase; or it might be only an exaggerated caution and a strange passion for secrecy which sealed Homer Sivewright’s lips. Once, when his patient was asleep, Lucius contrived to examine the panelling in front of the masked staircase, but he could discover no means of communication. If there were, as he fully believed, a sliding panel, the trick of it altogether baffled him. This failure worried him exceedingly. He had a morbid horror of that possible entrance to his patient’s room, which it was beyond his power to defend by bolt, lock, or bar, since he knew not the manner of its working. For worlds he would not have alarmed Mr. Sivewright, who was still weak as an infant, although wonderfully improved during the last few days. He was therefore compelled to be silent, but he felt that here was the one hitch in his scheme of defence from the hidden enemy. ‘After all, there is little need to torment myself about the mystery,’ he thought sometimes. ‘It is clear enough that these Winchers were guilty alike of the robbery and the attempt to murder. The greater crime was but a means of saving themselves from the consequences of the lesser; or they may possibly have supposed that their old master had left them well provided for in his will, and that the way to independence lay across his grave. It is hard to think that human nature can be so vile, but in this case there is scarcely room for doubt.’ He thought of that man whom he had seen in the brief glare of the frequent lightning—the man who had raised himself from his crouching attitude to look up at the lighted window on the topmost story, and had then scaled the wall. ‘The receiver of stolen goods, the medium by which they disposed of their booty, no doubt,’ he said to himself; ‘their crime would have been incomplete without such aid.’