"The lady's sister. Enid Henson was not at 218, Brunswick Square, on the night in question. Of that you may be certain. But it's a queer business altogether. Rascality I can understand. I am beginning to comprehend the plot of which I am the victim. But I don't mind admitting that up to the present I fail to comprehend why those girls evolved the grotesque scheme for getting assistance at your hands. The whole thing savours of madness." "I don't think so," David said, thoughtfully. "The girls are romantic as well as clever. They are bound together by the common ties of a common enmity towards a cunning and utterly unscrupulous scoundrel. By the merest accident in the world they discovered that I am in a position to afford them valuable advice and assistance. At the same time they don't want me to be brought into the business, for two reasons--the first, because the family secret is a sacred one; the second, because any disclosures would land me in great physical danger. Therefore they put their heads together and evolve this scheme. Call it a mad venture if you like, but if you consider the history of your own country you can find wilder schemes evolved and carried out by men who have had brains enough to be trusted with the fortunes of the nation. If these girls had been less considerate for my safety--" "But," Bell broke in eagerly, "they failed in that respect at the very outset. You must have been spotted instantly by the foe, who has cunningly placed you in a dangerous position, perhaps as a warning to mind your own business in future. And if those girls come forward to save you--and to do so they must appear in public, mind you--they are bound to give away the whole thing. Mark the beautiful cunning of it. My word, we have a foe worthy of our steel to meet." "_We_? Do you mean to say that your enemy and mine is a common one?" "Certainly. When I found my foe I found yours." "And who may he be, by the same token?" "Reginald Henson. Mind you, I had no more idea of it than the dead when I went to Longdean Grange to-night. I went there because I had begun to suspect who occupied the place and to try and ascertain how the Rembrandt engraving got into 218, Brunswick Square. Miss Gates must have heard us talking over the matter, and that was why she went to Longdean Grange to-night." "I hope she got home safe," said David. "The cab man says he put her down opposite the Lawns."