ld suggest that an alarm had been fixed. T.
B. stole carefully up the stairs, leaving the two men to guard the hall
below. At every landing he halted, and listened, but the house was
wrapped in silence, and he searched the third floor without mishap.

He recognized the corridor, having taken very careful note of certain
peculiarities, and a scratch on the side of the lift door, which he had
mentally noted for future reference, showed him he was on the right
track.

Unerringly and swiftly he passed along the passage till he came to the
big rosewood doors which opened upon the invalid's bedroom. He turned
the handle gently, it yielded, and he stepped noiselessly through the
door, and pushed the inner door cautiously. The room was dimly
illuminated, evidently by a night light, thought T. B., and he pressed
the door farther open that he might secure a better view of the
apartment, and then he gasped, for this was not the room he had been in
before.

It was a sumptuously arranged bureau, panelled in rosewood, and set
about with costly furniture. A man was sitting at the desk, busily
writing by the light of a table lamp; his back was toward T. B. The
detective pushed the door farther open, and suddenly the man at the desk
leapt up, and turning round, confronted the midnight visitor.

T. B. had only time to see that his face was hidden behind a black mask
which extended from his forehead to his chin. As soon as he saw T. B.
standing in the doorway, he reached out his hand. Instantly the room was
in darkness, and the door, which T. B. was holding ajar, was suddenly
forced back as if by an irresistible power, flinging the detective into
the corridor, which almost simultaneously was flooded with light. T. B.
turned to meet the smiling face of Dr. Fall.

The big man, with his white, expressionless countenance, was regarding
him gravely, and with amused resentment.

Where he had come from T. B. could only conjecture; he had appeared as
if by magic and was fully dressed.

"To what do I owe the honour of this visit, Mr. Smith?" he said, in his
dry, grim way.

"A spirit of curiosity," said T. B., coolly. "I was anxious to secure
another peep at your Mr. Moole."

"And how did he look?" asked the other, with a faint smile.

"Unfortunately," said T. B., "I have mistaken the floor, and instead of
seeing our friend, I have unexpectedly and quite unwittingly interrupted
a gentleman who, for reasons best known to himself, has hid