A waiter approached the table and addressed the Colonel--he was wanted on the telephone. During his absence, Heneage leaned back in his chair and relapsed into his usual imperturbability. He was known amongst his friends generally as the silent man. It was very seldom that he contributed so much to their discussions as upon this occasion. Perhaps for that reason his words, when he spoke, always carried weight. Mason changed his place and sat beside him. The others had wandered off into a discussion upon a new magazine. "Between ourselves, Heneage," Mason said quietly, "have you anything at the back of your head about Wrayson?" Heneage did not immediately reply. He was gazing at the little cloud of blue tobacco smoke which he had just expelled from his lips. "There is no reason," he declared, "why my opinion should be worth any more than any one else's. I think as highly of Wrayson as any of you." "Granted," Mason answered. "But you have a theory or an idea of some sort concerning him. What is it?" "If you really want to know," Heneage said, "I believe that Wrayson has kept something back. It is a very dangerous thing to do, and I believe that he realizes it. I believe that he has some secret knowledge of the affair which he has not disclosed--knowledge which he has kept out of his evidence altogether." "A--guilty--knowledge?" Mason whispered. "Not necessarily!" Heneage answered. "He may be shielding some one." "If you are right," Mason said anxiously, "it is a serious affair." "Very serious indeed," Heneage assented. "I believe that he is realizing it." The Colonel came back looking a little disturbed. "Sorry, boys, but I must be off," he announced. "Wrayson has just telephoned to ask me to go down and see him. I'm afraid he's queer! I've sent for a hansom." "Poor chap!" Mason murmured. "Let us know if any of us can do anything." The Colonel nodded and took his departure. The others drifted up into the billiard-room. Heneage alone remained seated at the end of the table. He was playing idly with his wineglass, but his eyes were fixed steadfastly, if a little absently, upon the Colonel's empty place. CHAPTER V ON THE TELEPHONE It was a little hard even for the Colonel to keep up his affectation of cheerfulness when he found himself alone with the man whom he had come to visit. His experience of life had been large and varied, but he had never yet seen so remarkable a change in any human being in twenty-four hours. There were deep black lines under his eyes, his cheeks were colourless, every now and then his features twitched nervously, as though he were suffering from an attack of St. Vitus' dance. His hand, which had lain weakly in the Colonel's, was as cold as ice, although there was a roaring fire in the room. He had admitted the Colonel himself, and almost dragged him inside the door. "Did you meet any one outside--upon the stairs?" he asked feverishly.