Gregson looked quite crest-fallen.

"I had no idea that you noticed that," he said.
"Have you been there?"

"No."

"Ha!" cried Gregson, in a relieved voice; "you should never
neglect a chance, however small it may seem."

"To a great mind, nothing is little," remarked Holmes,
sententiously.

"Well, I went to Underwood, and asked him if he had sold a
hat of that size and description. He looked over his books,
and came on it at once. He had sent the hat to a Mr. Drebber,
residing at Charpentier's Boarding Establishment,
Torquay Terrace. Thus I got at his address."

"Smart -- very smart!" murmured Sherlock Holmes.

"I next called upon Madame Charpentier," continued the
detective. "I found her very pale and distressed. Her
daughter was in the room, too -- an uncommonly fine girl she
is, too; she was looking red about the eyes and her lips
trembled as I spoke to her. That didn't escape my notice.
I began to smell a rat. You know the feeling, Mr. Sherlock
Holmes, when you come upon the right scent -- a kind of
thrill in your nerves. `Have you heard of the mysterious
death of your late boarder Mr. Enoch J. Drebber, of