I also made careful inquiries concerning the young Silesian, and had him pointed out to me. He had recently come from his own capital, and was remaining in London only for a short time. He was a relative of the ambassador, and was not here in any official capacity, it was stated. This might be true so far as it went, but at the same time he might be connected with the secret service. The professor said very little about his investigations, and I concluded he had met with no success. He had spent some hours with Lanning at the works, I knew, but if he had tapped any other sources of information he did not mention them. He was still engaged in his cubist's drawings when the telephone bell rang. "I'll go," he said as Zena jumped up; "I am expecting a message." He went into the hall, and when he returned told us that Lanning and Nixon were on their way to Chelsea. "I told them to 'phone me if anything happened," he said. "And you expected to hear from them?" I asked. "My name is Micawber when I am in a hole, and I wait for something to turn up. Waiting is occasionally the best way of getting to the end of the journey. We will hear what they have to say, Wigan, and then we shall possibly have to get a move on." Evidently he had a theory, but he would say nothing about it. He amused himself by explaining that mechanical action, such as drawing meaningless lines and curves, as he had been doing, had the effect of giving the brain freedom to think, and declared that it was during times of this sort of freedom that inspiration most usually came. He was still engrossed with the subject when Lanning and Nixon arrived. Quarles introduced them to Zena, saying that she always helped him in his investigations. "Oh, no, not as a clairvoyant," he said with a smile as both men looked astonished. "She just uses common sense, a very valuable thing in detective work, I can assure you." "Are you any nearer a solution?" Lanning asked. "I thought you had come to give me some information," Quarles returned. "I have, but--" "Sit down, then, and to business. I am still wanting facts, which are more useful than all my theories." "Mademoiselle Duplaix telephoned to me this morning," said Lanning. "A man called on her to-day, a mysterious foreigner. He gave no name, but she thinks he was a Silesian, although he spoke perfect French. He talked to her in French, his English being of a fragmentary kind. He asked her to give him the plans of the new aeroplane. You can imagine her surprise. When she said she had got no plans he expressed great astonishment and plunged into the whole story of how I had been robbed. Until that moment Mademoiselle knew nothing of what had happened in my flat, but this foreigner had evidently got hold of the whole story." "Who had told him to call upon her?" Quarles asked.