"Oh yes. They first met about three months ago, and after that Mr Trustram came here several times weekly. The doctor went to stay at his country cottage near Dorking for the week-end, about a fortnight ago." "Did you ever discover the reason of those conferences?" Jack Sainsbury asked. "I mean, did you ever overhear any of their conversations?" "Sometimes, sir. But not very often," was Thomasson's discreet reply. "They frequently discussed the war, and the spy-peril, in which--as you know--the doctor was actively interesting himself." Upon Jack Sainsbury's countenance a faint smile appeared. He now discerned the reason of the visits of that Admiralty official to the man who had been so suddenly and mysteriously stricken down. He exchanged glances with Sir Houston, who, a moment before, had been searching a cigar cabinet which had hitherto escaped their notice. At Rees's suggestion, Jack Sainsbury went to the telephone and rang up Charles Trustram, to whom he briefly related the story of the tragic discovery. Within twenty minutes Trustram arrived, and, to the detective, told the story of the events of the evening: how they had met by appointment at Prince's Restaurant at half-past seven, had dined together, and then he had accompanied the doctor back to Wimpole Street about half-past nine, where they had sat smoking and chatting. "Jerrold seemed in quite good spirits over the result of an inquiry he had been making regarding a secret store of petrol established by the enemy's emissaries somewhere on the Sussex coast," Mr Trustram explained. "He had, he told me, disclosed it to the Intelligence Department, and they were taking secret measures to watch a certain barn wherein the petrol was concealed, and to arrest those implicated in the affair. He also expressed some anxiety regarding Mr Sainsbury, saying that he wished he could see him to-night." Then, turning to Jack, he added: "At his request I rang up your flat at Hampstead, but you were not in." "Why did he wish to see me?" "Ah! that I don't know. He told me nothing," was the Admiralty official's reply. "While I was sitting here with him I was rung up three times--twice from my office, and once by a well-known man I had met for the first time that afternoon--Mr Lewin Rodwell." At mention of Rodwell all present became instantly interested. "How did Mr Rodwell know that you were here?" inquired the detective quickly. "That's a mystery. I did not tell him." "He might have rung up your house, and your servant may possibly have told him that you were dining with Jerrold," Sir Houston suggested. "That may be so. I will ask my man." "What did Mr Rodwell want?" Rees asked.