"I tell you, Emerson, that is the fellow. I could swear to him anywhere. What he is got up like that for I cannot tell you, but I should not be surprised if he is one of that Bow Street gang. He called himself Mark Thorndyke, and Chetwynd said that he was a gentleman of property; but that might have been part of the plant to catch us. I have never been able to understand how a raw countryman could have caught you palming that card. I believe that fellow is a Bow Street runner; if so, it is rum if we cannot manage to get even with him before we go. It seemed to me that luck had deserted us altogether; but this looks as if it was going to turn again. Let's go after him."

Keeping some fifty yards behind him, they watched Mark to his lodgings, waited until he came out again, and followed him to a public house.

"He is acting as a detective, sure enough," Emerson said. "The question is, what are we to do next?"

In half an hour Mark came out again. Several people nodded to him as he passed them, but they saw a big man, who happened to be standing under a lamp, turn his back suddenly as Mark approached him, and, after he had passed, stand scowling after him, and muttering deep curses. Flash at once went up to him. "Do you know who that fellow is, my man?" The fellow turned savagely upon him.