ive 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.

Startled thus out of fitful slumber by the noise at her door, she
sprang from her bed to the floor, every terror that lurked in her
acutely tense mind and diseased imagination starting up and almost
overwhelming her. The idea of flight--one of the strongest of all
instincts--seized upon her, and she ran to the door, beyond all control
of reason. She drew the bolt and flung the door wide open, and then
fled wildly down the passage, the appalling hissing and rasping gurgle
ringing in her ears apparently with a thousandfold intensity. But the
passage was in absolute darkness, and she had not taken a half-dozen
steps when she tripped upon an unseen object on the floor. She fell
headlong upon it, encountering in it a large, soft, warm substance that
writhed and squirmed, and from which came the sounds that had awakened
her