The weapon Vernon proposed to use towards his dangerous foe was that supplied by the chance remark of Lady Corsoon that Maunders might be The Spider. When she departed with the assurance that there was nothing to be afraid of for at least one month, Vernon sat silently in his chair, thinking over what had been said. After all, it did not seem impossible that Maunders should be this arch-scoundrel, for whom the police were so eagerly seeking. To Vernon's own knowledge, the young man did not receive large sums from Mrs. Bedge, and he had no other source of income. Yet, as Vernon had seen, he contrived to live like a prince on nothing a year. Perhaps, like the amiable and talented Mrs. Rawdon Crawley, he managed to keep up his princely appearance by spending other people's money--that is, by getting deeply into debt. But Vernon knew that Maunders did not owe one penny.

He came by the information by having, at the request of the late Mr. Dimsdale, searched into Maunders' private life some months previously. The old ex-police-commissioner, seeing that his daughter was infatuated with the young man, hoped to learn something to his discredit, and so asked Vernon--whom he knew already as Nemo--to make an examination. Of course, Vernon did not guess at the time that Mr. Dimsdale wished to find something to the discredit of an undesirable suitor, and merely thought that the old man was anxious to learn if Maunders was a fit husband for his daughter. In fact, Vernon believed that he was doing his old schoolfellow a good turn in probing his life. He certainly learned that Maunders owed nothing and always settled his debts scrupulously--presumably on money allowed by Mrs. Bedge; so he presented his report to Dimsdale with the remark that Maunders, at all events, was an honest man. Now the case assumed a different aspect with Mrs. Bedge's confession of poverty--a confession which was supported as true by her anxiety to become Ida's paid companion. Since Maunders paid his debts and lived like a millionaire in embryo, how did he manage to fill his purse? Lady Corsoon had provided a very reasonable reply to this serious question. He was The Spider.

"But, hang him, he's not clever enough," muttered Vernon, rising to pace the narrow confines of his office at this point of his meditations. "He's cunning and smart and observant and unscrupulous. But The Spider is a genius and manages his affairs in a far-seeing way, which does not suggest Maunders. Conny is shallow in many ways, and for the present would sacrifice the future. No, The Spider never does that. He waits and plans and arranges his operations in such a way that he can never be captured. No, feasible though it seems, I can't see Constantine as that master-criminal."

But again Vernon reflected that when the trap had been arranged between him and the dead man the window of the library had been open, and, as Mr. Dimsdale had mentioned in his subsequent letter, with wrath, Maunders had called at the moment. In fact, he had been round the corner of the bungalow nearest to the library with the two ladies. Now, it was not impossible that in passing the library, light-footed as he was (and Maunders trod like a cat), he might have lingered at the sound of voices. Thus he might have gained the necessary knowledge of the trap, which he had afterwards utilized to inveigle Vernon to the West Kensington house. That is, presuming he was The Spider; and the name of Lucy Corsoon used in the wire was the very name which Maunders, knowing Vernon's love for the girl, would employ. Finally, Maunders had been at the ball, and it would have been easy for him, masked and cloaked as he was, to steal into the library and commit the crime, afterwards mingling with the guests in all apparent innocence. On these grounds Vernon began to believe that Lady Corsoon might be correct in her assumption. But always there came the doubt that Maunders was too shallow to be the arch-rogue. He was clever, but certainly not a genius, whereas The Spider was a Napoleon amongst the criminal fraternity.

"In one way I can prove something," said Vernon to himself. "If Maunders did enter the library he must have been absent from the ballroom for some time. I shall go to 'Rangoon' and ask questions without letting it be seen why I ask them. Then I can learn for certain about his movements on that night. Moreover, I can interview Miss Dimsdale and learn how she is disposed towards the Colonel. Finally, I'll see if he is right in thinking that Miss Hest's influence is harmful to her in any way."

Having come to this decision, he repaired the ensuing day to Hampstead, fully determined to set his doubts at rest. A glance at the agony column of the _Daily Telegraph_ had assured him that Lady Corsoon had carried out his suggestion. Under the initial "X," she asked for one month's time to consider the matter of "S." This undoubtedly would be accorded to her, as it was The Spider's policy never to hurry his victims. He robbed them in a most graceful and easy-going fashion, and so dexterously, that his victims rather congratulated themselves that they had so honest a criminal tradesman to deal with. So Lady Corsoon's secret was safe for a month. Before the expiration of that period Vernon hoped to lay hands on the rogue who had baffled the police for so long. But in his heart he did not expect to find Maunders in the grip of the law.

At first Vernon was refused admittance by the butler, but on insisting and on sending in his card he was shown into the central hall. Shortly Miss Hest made her appearance with a smiling but somewhat serious face. She looked extremely tall and handsome in a black-browed way as she advanced towards the visitor.

"How are you, Mr. Vernon," she said, shaking hands politely; "is your business with Miss Dimsdale very important? She is not well to-day. I have just been bathing her forehead with eau-de-cologne."

"Oh, I have just come to make an afternoon call," replied Vernon easily. "I am sorry to hear that Miss Dimsdale is ill."

Frances sighed. "She has never been the same since her poor father's terrible death. She loved him as dearly as he loved her, you know, Mr. Vernon, so the shock was great."