"The next morning Mr. Knopf, black hair and beard and all, was himself again. The whole trick lay in one simple art, which those two cunning rascals knew to absolute perfection, the art of impersonating one another.
"They are brothers, presumably—twin brothers, I should say."
"But Mr. Knopf—" suggested Polly.
"Well, look in the Trades' Directory; you will see F. Knopf & Co., diamond merchants, of some City address. Ask about the firm among the trade; you will hear that it is firmly established on a sound financial basis. He! he! he! and it deserves to be," added the man in the corner, as, calling for the waitress, he received his ticket, and taking up his shabby hat, took himself and his bit of string rapidly out of the room.
CHAPTER VII
THE YORK MYSTERY
The man in the corner looked quite cheerful that morning; he had had two glasses of milk and had even gone to the extravagance of an extra cheese-cake. Polly knew that he was itching to talk police and murders, for he cast furtive glances at her from time to time, produced a bit of string, tied and untied it into scores of complicated knots, and finally, bringing out his pocket-book, he placed two or three photographs before her.
"Do you know who that is?" he asked, pointing to one of these.
The girl looked at the face on the picture. It was that of a woman, not exactly pretty, but very gentle and childlike, with a strange pathetic look in the large eyes which was wonderfully appealing.