He sat staring at the sheet of paper, trying to fit this new discovery into the scheme of things. But it seemed to him an insoluble puzzle. Was Mr. Duke not really the innocent, kindly old gentleman he had fancied, but rather a member, if not the author, of some deep-seated conspiracy? If he had written this note, why had he not mentioned the fact when Vanderkemp was being discussed? Why had he shown surprise when he received Schoofs’ letter saying that the traveller had crossed to London? What was at the bottom of the whole affair? An idea struck him, and he examined the letter more closely. “Are you sure this is really Mr. Duke’s signature?” he asked slowly. Mr. Schoofs looked at him curiously. “Why, yes,” he answered. “At least, it never occurred to me to doubt it.” “You might let me see some of his other letters.” In a few seconds half a dozen were produced, and French began whistling below his breath as he sat comparing the signatures, using a lens which he took from his pocket. After he had examined each systematically, he laid them down on the table and sat back in his chair. “That was stupid of me,” he announced. “I should have learnt all I wanted without asking for these other letters. That signature is forged. See here, look at it for yourself.” He passed the lens to Schoofs, who in his turn examined the name. “You see, the lines of that writing are not smooth; they are a mass of tiny shakes and quivers. That means that they have not been written quickly and boldly; they have been slowly drawn or traced over pencil. Compare one of these other notes and you will see that while at a distance the signatures look identical, in reality they are quite different. No, Mr. Duke never wrote that. I am afraid Mr. Vanderkemp has been the victim of some trick.” Schoofs was visibly excited. He hung on the other’s words and nodded emphatically at his conclusions. Then he swore comprehensively in Dutch. “Good heavens, Inspector!” he cried. “You see the significance of all that?” French glanced at him keenly. “In what way?” he demanded. “Why, here we have a murder and a robbery, and then we have this, occurring at the very same time. . . . Well, does it not look suggestive?” “You mean the two things are connected?” “Well, what do you think?” Mr. Schoofs replied with some impatience. “It certainly does look like it,” French admitted slowly. Already his active brain was building up a theory, but he wanted to get the other’s views. “You are suggesting, I take it, that Vanderkemp may have been concerned in the crime?” Schoofs shook his head decidedly. “I am suggesting nothing of the kind,” he retorted. “That’s not my job. The thing merely struck me as peculiar.”