“Well, we’ve traced them one step farther, Chick,” Nick remarked to his first assistant as they left, “but we haven’t tracked them down, by a long shot. Grantley doubtless went through the Metropolitan Building to Fourth Avenue. There he either took the subway, hailed another taxi, or—hold on, though! Maybe there’s something in that! I wonder——”

“Now, what?” Chick asked eagerly.

“You remember Doctor Chester, one of the six young physicians, who was mixed up with Grantley in that vivisection case?”

“Of course I do,” his assistant answered. “He has taken another name and given up his profession—on the surface at least. He’s living on East Twenty-sixth Street——”

“Exactly—a very few blocks from the Metropolitan Building!” interrupted his chief.

“You mean——”

“I have a ‘hunch,’ as Patsy would call it that Grantley has taken Helga Lund to Chester’s house. Chester had rented one of those old-fashioned, run-down bricks across from the armory. It’s liable to be demolished almost any day, to make way for a new skyscraper, and he doubtless gets it for a song. He can do what he pleases there, and I wouldn’t be surprised to find that Grantley had been paying the rent in anticipation of something of this sort. They undoubtedly think that we lost sight of Chester long ago.”

“By George, I’ll wager you’re right, chief!” exclaimed Chick. “The fact that we’ve traced Grantley to the Metropolitan Building certainly looks significant, in view of Chester’s house being so near to it. It’s only about five minutes’ walk, and a man with Grantley’s resourcefulness could easily have made enough changes in his appearance and that of Miss Lund, while in the Metropolitan Building, to have made it impossible for the two who entered Chester’s house to be identified with those who had left the Wentworth-Belding an hour or so before.”

“That’s the way it strikes me,” agreed the detective. “And, if the scoundrel took her there last night, they are doubtless there now. I think we’re sufficiently justified in forcing our way into the house and searching it, and that without delay. We don’t know enough to take the police into our confidence as yet; therefore, the raid will have to be purely on our own responsibility. We must put our theory to the test at once, however, without giving Grantley any more time to harm the actress. Heaven knows he’s had enough opportunity to do so already!”

“Right! We can’t wait for darkness or reënforcements. It will have to be a daylight job, put through just as we are. If we find ourselves on the wrong scent, Chester will be in a position to make it hot for us—or would be, if he had any standing—but we’ll have to risk that.”