Lydon might not be able to lay claim to any remarkable brilliance of intellect. At Harrow and Oxford his progress had been steady and respectable, but he had not distinguished himself like his friend Craig, for instance, to whom the acquisition of knowledge was an easy task, whose mental alertness was the delight of his masters and tutors. But he was a shrewd young fellow, and endowed with a considerable fund of common-sense. He also possessed a dogged spirit of determination. When he once took a thing up he persevered with it, and was not easily daunted by obstacles. There were, at the present moment, two things he was resolved to find out by some means or other--the precise nature of Stormont’s business and the life history of the dark, handsome girl known as Zillah Mayhew. He thought the best thing he would do as a start was to go and consult Shelford, the solicitor in Lincoln’s Inn. As he was pretty well master of his own time, he paid him an early morning visit before he went to his business in Victoria Street. That genial gentleman was disengaged and saw him at once. To him the young man related his accidental meeting with Miss Mayhew at the house of a mutual friend, and the two remarkable facts that she had a blemish on the neck, and was wearing a rather original piece of jewellery, similar in design to one he had seen in the drawing-room of the Villa des Cyclamens when he had called there to condole with Madame Makris on the tragedy. Mr. Shelford was very much impressed, as Lydon was sure he would be: “One or other of the facts, taken singly, would not lead one very far,” he observed. “There are no doubt heaps of girls who may have a mark of this kind, and I suppose there is no piece of jewellery which is absolutely unique, which has not several replicas. But taken in conjunction, the evidence is very remarkable. Well, I suppose you want to go further into it. What you have learned about this young lady in the ordinary course does not satisfy you?” Lydon answered that it certainly did not, that he wanted to have his suspicions disproved or confirmed. What did Shelford advise? The solicitor was quite ready with an answer. “If you or I were to undertake the task of tracing the history of Miss Mayhew, I expect we should find out next to nothing. Such a business is not the least in our line. But there is, fortunately, a class of men who are experts in this kind of thing, and perform wonders if you give them something to go on. You have heard of course of private inquiry agents, perhaps may have employed one in your time?” “I have heard of them, naturally. Some of them advertise their skill in tracking faithless wives and erring husbands. But I have never had occasion to avail myself of their services.”