expert to notice that the envelope has passed through the "cabinet noir." I saw, however, in this worn envelope the two edges were coming apart, and at once admitted the truth of the Earl's assertions. He was intensely shrewd; scarcely any minute detail escaped him. "Well," he said reflectively, at last, "there is but one person from whom we may ascertain the truth." "Who?" "Your wife." "But she has disappeared." "We must trace her. She must not escape us," he cried fiercely, with set teeth. "She has wronged you and acted in collusion with a man who has betrayed his country and met with a tragic end, even if she herself did not actually sell the copy of the secret convention to our enemies-- which appears to me more than likely." "What causes you to believe this?" I inquired, surprised at his sudden assertion. "I have a reason," he answered quickly, with an air of mystery. The cold manner of the expert diplomatist had again settled upon him. "If it is as I expect, I will show her no mercy, for it is upon me, as Foreign Minister of Her Majesty, that opprobrium has fallen." "But she is still my wife," I observed, for even at that moment, when I had discovered her false and base, I had not ceased to regard her with a passionate affection. "Wife!" he snarled angrily. "You would have been a thousand times better dead than married to such as she." Then he added, "Remain here. I am going to the telephone to apprise Scotland Yard of her flight. She only left to-night after the mails were gone, therefore if we have the ports watched we may yet find her." And he left me, his quick footsteps echoing down the long corridor. The moment he had gone I went to his table. Some sudden curiosity prompted me to endeavour to ascertain what he had been gazing upon so intently while my back had been turned in penning the instructions to Sir Philip Emden. Quickly I took his keys, and, unlocking the tiny drawer, opened it. Inside there reposed a highly-finished cabinet portrait of my wife. Amazed to find this picture in the possession of my chief, I took it in my hands and stood agape. Its pose was unfamiliar, but the reason I had never before seen a copy of it was instantly made plain. It bore the name of a well-known St Petersburg photographer. Ella had lied to me when she had denied ever having been in Russia. CHAPTER TWENTY FIVE. THE MAN OF THE HOUR.