'Oh!' said Elsie. 'Then you know all--as much as I know.' 'Observe,' George interposed, 'that I know nothing as yet.' 'Wait a moment, George. Learn that I have myself known Mr. Edmund Gray for a fortnight. You will think, perhaps, that I ought to have told you before. Well--but there is a reason--besides, the way, to begin with, did not lie quite clear before me. Now the time has come when you should advise as to the best course to follow.' 'You have certainly been more mysterious than any oracle, Elsie. Yet you will bear witness, if it comes to bearing witness, that I accepted your utterances and believed in them.' 'You certainly did, George.--And now, Athelstan, tell him the whole.' 'In one word then--Edmund Gray, the man we have been looking after so long, is none other than Edward Dering, of 12 New Square, Lincoln's Inn, Solicitor.' 'I don't understand,' said George, bewildered. 'Say it all again.' Athelstan repeated his words. 'That is my discovery, too,' said Elsie. 'Now you know all, as you understand.' 'But I don't understand. How can one man be another man?' 'I sat beside one man,' Athelstan added, 'for an hour and more; and lo! all the time he was another man.' 'And still I am fogged. What does it mean?' 'It means, George, what you would never suspect. The one man received me as a stranger. He knew nothing about me: he had never heard my name, even. Yet the other man knows me so well. It was very odd at first. I felt as if I was talking to a sleep-walker.' 'Oh!' cried George, 'I know now. You have seen Mr. Dering in a kind of sleep-walking state-- I too have seen him thus. But he said nothing.' 'You may call it sleep-walking if you like. But, George, there is another and a more scientific name for it. The old man is mad. He has fits of madness, during which he plays another part, under another name. Now, do you understand?' 'Yes--but--is it possible?' 'It is more than possible; it is an actual certainty. Wait. Let Elsie tell her story.' Then Elsie began, with a little air of triumph, because it is not given to every young lady to find out what all the men have failed to find.