"There ought to be some response to that, you know, Mr. Allerdyke," remarked Chettle. "Somebody must remember and know something about that young fellow. But, upon my soul, as I said to Blindway just now, I don't know whether that bill's a mere advertisement or a—death warrant!"

"Death warrant!" exclaimed Allerdyke. "What d'you mean?"

Chettle chuckled knowingly.

"Mean," he said. "Why, this—if that young fellow who led pugs about, and talked to Mamselle Lisette in Kensington Gardens, is another of the cat's paws that this gang evidently made use of, I should say that when the gang sees he's being searched for, they'll out him, just as they outed her and Lydenberg. That's what I mean, Mr. Allerdyke—they'll do him in themselves before anybody else can get at him! See?"

Allerdyke saw. And when the detective had gone, he threw himself into a chair, lighted one of his strongest cigars, drew pen, ink, and paper to him, and began to work at his problem with a grim determination to evolve at any rate a clear theory of its possible solution.

CHAPTER XXIV

CONCERNING CARL FEDERMAN

Next morning, as Allerdyke was leaving the hotel with the intention of going down to Gresham Street, one of the hall-porters ran after and hailed him.

"You're wanted at the telephone, sir," he said. "Call for you just come through."

Allerdyke went back, to find himself hailed by Blindway. Would he drive on to the Yard at once and bring Mr. Fullaway with him?—both were wanted, particularly in connection with the Perrigo information.