"As a scientist," he replied deliberately, "the theory, of course,
does appeal to me, especially in the ingenious way in which that
writer applied it. However, as a detective"--he shook his head
slowly--"I must deal with facts--not speculations. It leaves much
to be explained, to say the least,"

Just then the door buzzer sounded and Carton himself sprang to
answer it.

"That's Mrs. Blackwell now--her mother. I told her that I was
going to take the case to you, Kennedy, and took the liberty of
asking her to come up here to meet you. Good-afternoon, Mrs.
Blackwell. Let me introduce Professor Kennedy and Mr. Jameson, of
whom I spoke to you."

She bowed and murmured a tremulous greeting. Kennedy placed a
chair for her and she thanked him.

Mrs. Blackwell was a slender little woman in black, well past
middle age. Her face and dress spoke of years of economy, even of
privation, but her manner was plainly that of a woman of gentle
breeding and former luxury. She was precisely of the type of
decayed gentlewoman that one meets often in the city, especially
at some of the middle-class boarding-houses.

Deeply as the disappearance of her daughter had affected her, Mrs.
Blackwell was facing it bravely. That was her nature. One could
imagine that only when Betty was actually found would this plucky
little woman collapse. Instinctively, one felt that she claimed
his assistance in the unequal fight she was waging against the