"Now in this affair we must be perfectly candid with each other. You must conceal nothing from me." "I have concealed nothing," I protested, surprised at his curious attitude, as though he held me in some suspicion. "I don't allege that you have," he answered. "But I want you to answer truthfully a question which is of highest importance. I want you to tell me whether, on the afternoon of the day you were called by Patterson to Kensington, your friend Cleugh was here, at home." "No, he certainly wasn't. I arrived home first, and he came in perhaps ten minutes or a quarter of an hour later than usual," I answered, wondering what connexion this could have with the inquiry. "And after you made the discovery you did not telegraph or communicate with him in any way? I take it that you were surprised to meet him in that house." "Certainly I was," I responded. "But he had an appointment with Lily Lowry, and finding that she could not keep it, he came along to Kensington to ascertain the nature of the event about which Patterson had wired to me." The detective's features relaxed into a strange smile. "Would you be surprised then to know that your friend never called at the Police-Station on that evening, but went straight to Phillimore Place and there joined me while you were absent inquiring of the neighbours? That very evening I inquired of the constable on duty at the door of the station, and of others, all of whom told me that no one had called to inquire for Patterson except yourself." "That's certainly extraordinary," I said in wonderment. "Yes," he observed mechanically. "It's a very curious fact; one which appears to prove that he knew something more of the mysterious occurrence than he has admitted--in fact, that he was aware of it long before we were." "What!" I gasped, gazing at my companion in alarm. "Surely you don't mean that you suspect Dick of having had any hand in the affair?" Then, at that instant, I recollected how, when I had received the telegram on that memorable evening, his face had suddenly changed, and his hand had trembled. CHAPTER EIGHTEEN. "YOU WILL NEVER KNOW--NEVER!" Dick returned about eleven, and shortly afterwards Boyd swallowed another whisky-and-soda and left. I thought my friend started slightly at finding the detective with me, but he betrayed not the slightest annoyance. Indeed, he himself started the discussion regarding the mystery, appearing in no way loth to discuss it in all its phases.