“That is curious,” Hopford exclaimed, “because when Mrs. Robertson and Michaud came face to face in Dieppe the other day, they apparently did not know each other. A friend of mine, Captain Preston, said so in a letter to Doctor Johnson.” “Not Captain Charles Preston who is going to marry a girl called Yootha Hagerston?” the other detective asked quickly, now speaking for the first time. “That is the man,” Hopford replied. “I served under him during the war, and I know Miss Hagerston too.” The detective glanced across at his female colleague. “Isn’t that a coincidence?” he said. “Oh, coincidences never surprise me,” she answered with a shrug. “But it points to further collusion,” the man said. “Then I take it,” Llanvar put in, “there exists in London at the present time, and has existed for a year or more, some sort of organization for extorting money in considerable sums from rich and well-known people by means of direct or indirect blackmail?” “Not only that,” the woman answered. “I am in a position to know that some members of the organization have levied blackmail on each other. There is no honor among miscreants of that type. They would blackmail their own parents if they got the chance, and could benefit. Such people deserve life sentences. Yet in spite of the cunning and cleverness of this particular gang I think we are on the right road to tracking them all down now, although they do pretend to belong to the best society, and no doubt have influential friends.” Hopford felt elated as he wandered homeward that night, arm in arm with his host, the mental specialist, Idris Llanvar. Each member of the little gathering had, during the informal conference, contributed some link, or part of a link, to the chain of evidence they were forging between them to justify steps being taken to arrest Jessica and the people whom they now knew beyond doubt to be her accomplices in crime. The town of Singapore had been mentioned incidentally, and Llanvar had provided some useful data. Angela Robertson and Fobart Robertson her husband, Timothy Macmahon, Julius Stringborg, and his wife Marietta, Aloysius Stapleton, and two or three more had apparently, when living in Shanghai, formed an exclusive little clique concerning which the strangest of rumors had been rife. The rumor most commonly credited was that the clique was actively interested in the secret exportation of a peculiarly potent drug said to possess several remarkable attributes. To what country or countries they exported it, nobody had been able to discover, but “on good authority” it was declared that high officials in Shanghai, Hong Kong and other important ports were in the habit of receiving heavy bribes not to notice what was happening.