The captain looked at the detective with a puzzled air.
"Three. The strongest men in your district."
"Nevertheless, I want three strong men; and for that matter, prudence really advises me to take twenty."
At one o'clock the next morning a cautious, scratching sound might have been heard in the ceiling of the surgeon's operating-room. Shortly afterwards the skylight sash was carefully raised and laid aside. A man peered into the opening. Nothing could be heard.
"That is singular," thought the detective.
He cautiously lowered himself to the floor by a rope, and then stood for some moments listening intently. There was a dead silence. He shot the slide of a dark-lantern, and rapidly swept the room with the light. It was bare, with the exception of a strong iron staple and ring, screwed to the floor in the centre of the room, with a heavy chain attached. The detective then turned his attention to the outer room; it was perfectly bare. He was deeply perplexed. Returning to the inner room, he called softly to the men to descend. While they were thus occupied he re-entered the outer room and examined the door. A glance sufficed. It was kept closed by a spring attachment, and was locked with a strong spring-lock that could be drawn from the inside.
"The bird has just flown," mused the detective. "A singular accident! The discovery and proper use of this thumb-bolt might not have happened once in fifty years, if my theory is correct."
By this time the men were behind him. He noiselessly drew the spring-bolt, opened the door, and looked out into the hall. He heard a peculiar sound. It was as though a gigantic lobster was floundering and scrambling in some distant part of the old house. Accompanying this sound was a loud, whistling breathing, and frequent rasping gasps.
These sounds were heard by still another person--the surgeon's wife; for they originated very near her rooms, which were a considerable distance from her husband's. She had been sleeping lightly, tortured by fear and harassed by frightful dreams. The conspiracy into which she had recently entered, for the destruction of her husband, was a source of great anxiety. She constantly suffered from the most gloomy forebodings, and lived in an atmosphere of terror. Added to the natural horror of her situation were those countless sources of fear which a fright-shaken mind creates and then magnifies. She was, indeed, in a pitiable state, having been driven first by terror to desperation, and then to madness.