As Parr came in his assistant gave him a sealed envelope. He glanced at the typewritten address, and then laid it on Yale’s outstretched hand. “Tell me who sent that?” he said, and Yale laughed. “A very small man with an absurd yellow beard; he talks through his nose and keeps a shop.” A slow smile dawned on Parr’s face. Yale added: “And that isn’t psychometry, because I happen to know it is from Mr. Johnson of Mildred Street.” He chuckled at the inspector’s blank expression, and when they were alone, explained. “I happen to know that you discovered the place to which all the Crimson Circle messages were sent. I, on the contrary, have known of its existence for a long time, and every message which has been sent to the Crimson Circle has been read by me. Mr. Johnson told me you were making inquiries, and I asked him to give you a very full explanation in the addressed envelope which you sent to him.” “So you knew it all the time?” asked Parr slowly. Derrick Yale nodded. “I know that messages intended for the Crimson Circle have been addressed to this little newsagent, and that every afternoon and evening a small boy calls to collect them. It is a humiliating confession to make, but I have never been able to trace the person who picks the boy’s pocket.” “Picks his pocket?” repeated Parr, and Yale enjoyed the mystery. “The boy’s instructions are to put the letters in his pocket, and to walk into the crowded High Street. Whilst he is there somebody takes them from his pocket without his being any the wiser.” Inspector Parr sat down on the chair which Yale had vacated, and rubbed his chin. “You’re an amazing fellow,” he said. “And what else have you discovered?” “What I have all along suspected,” said Yale, “that Thalia Drummond is in communication with the Crimson Circle and has given him every scrap of information which she has been able to gather.” Parr shook his head. “What are you going to do about that?” “I told you all along that she would lead us to the Crimson Circle,” said Yale quietly, “and sooner or later I am sure my predictions will be justified. It is nearly two months since I induced our friend who keeps a small newsagent’s shop to which letters may be addressed, to give me the first look over all letters addressed to Johnson. He wanted a little inducing, because our newsagent is a very honest, straightforward man, but it is my experience, and probably yours, that the mere suggestion that a man is assisting the cause of justice will induce him to commit the most outrageous acts of disloyalty. I took the liberty of suggesting, without stating, that I was a regular police officer; I hope you don’t mind.” “There are times when I think you should be a regular police officer,” said Parr. “So Thalia Drummond is in communication with the Crimson Circle?” “I shall continue to employ her, of course,” said Yale. “The closer she is to me, the less dangerous she will be.” “Why did Froyant go abroad?” asked Parr.