'He cannot write to two men,' said Athelstan. 'There must be a border-land between the waking and the dreaming, when the two spirits of Edmund Gray and Edward Dering contend for the mastery, or when they command each other—when Edmund Gray endorses cheques and Edward Dering writes letters and conducts transfers for his client—his double—himself.'
'I have seen him in such a state,' said George. 'At the time I never suspected anything but a passing trouble of mind, which caused him to be so wrapped up in his thoughts as not to be able to distinguish anything. He was then, I doubt not now, carrying out the instructions of Edmund Gray, or he was Edmund Gray acting for himself. Checkley whispered not to disturb him. He said that he had often seen him so.'
'I have never tried to understand,' said Elsie. 'But I saw that Edmund Gray was Mr. Dering gone mad, and that he himself, and nobody else, was the perpetrator of all these forgeries; and I have been trying to discover the best way—the kindest way to him—the surest way for us, of getting the truth known.—George, this is the secret of my mysterious movements. This is why I have not given you a single evening for a whole fortnight. Every evening—both Sundays—I have spent with this dear old man. He is the most delightful—the most gentle—the most generous—old man that you ever saw. He is full of ideas—oh! quite full—and they carry you out of yourself, until you awake next morning to find that they are a dream. I have fallen in love with him. I have had the most charming fortnight—only one was always rather afraid that he might come to himself, which would be awkward.'
'Well, Elsie, have you found a way?'
'I think I have. First, I have discovered that when he is surrounded with things that remind him of Edmund Gray, he remains Edmund Gray. Next, I have found out that I can, by talking to him even at his office, when he has his papers before him, turn him into Edmund Gray.'
'You are a witch, Elsie.'
'She is,' said George, looking at her in the foolish lover's way. 'You see what she has turned me into—a long time ago, and she has never turned me back again.'
'I have been thinking too,' said Athelstan. 'For our purposes, it would be enough to prove the identity of Edmund Gray and Edward Dering. That explains the resemblance of the handwriting and of the endorsement. My commissionaire's recollection of the man also identifies the cheque as drawn by himself for himself under another name. It explains the presence of the notes in the safe. It also shows that the long series of letters which passed between him and the broker were written by himself for himself. Here, however, is a difficulty. I can understand Edward Dering believing himself to be Edmund Gray, because I have seen it. But I cannot understand Edward Dering believing himself to be the Solicitor to Edmund Gray and writing at his command.'
'But I have seen him in that condition,' said Elsie. 'It was while he was changing from one to the other. He sat like one who listens. I think that Edmund Gray was at his elbow speaking to him. I think I could make him write a letter by instruction from Edmund Gray. That he should believe himself acting for a client in writing to the broker is no more wonderful than that he should believe himself another man altogether.'
'Show me, if you can, the old man acting for an imaginary client. Meantime, I mentioned the point as a difficulty. Prove, however, to Mr. Dering and to the others concerned that he is Edmund Gray, and all is proved. And this we can do by a host of witnesses.'