She thought about this all night. Now, when one has a gleam or glimmer of an idea, when one wants to disengage a single thought from the myriads which cross the brain, and to fix it and to make it clear, there is nothing in the world so good as to talk about it. The effort of finding words with which to drag it out makes it clearer. Every story-teller knows that the mere telling of a story turns his characters, who before were mere shadows, and shapeless shadows, into creatures of flesh and blood. Therefore, in the morning she began upon the thought which haunted her. 'Athelstan,' she said, 'do you know anything about somnambulism?' 'I knew a man once in California who shot a grizzly when he was sleep-walking. At least, he said so. That's the sum of my knowledge on the subject.' 'I want to know if people often walk about in the daytime unconscious?' 'They do. It is called wool-gathering.' 'Seriously, Athelstan. Consider. George saw Mr. Dering arrive in a state of unconsciousness. He saw nobody in the room. He opened the safe and placed some papers there. Then he locked the safe. Then he sat down at the window. Presently he awoke, and became himself again. If he did that once, he might do it again.' 'Well? And then?' 'You heard yesterday about the letters, and the placard and the Socialist tracts. Now Checkley couldn't do that. He couldn't, and he wouldn't.' 'Well?' 'But Mr. Dering could. If he had that attack once, he might have it again and again. Why, he constantly complains of forgetting things.' 'But the letters yesterday were addressed to Edmund Gray. How do you connect Edmund Gray with Edward Dering?' 'I don't know. But, my dear brother, the more I think of this business, the more persuaded I am that Checkley is not the prime mover, or even a confederate.' 'The same hand has doubtless been at work throughout. If not Checkley's aid to make that hand possible and successful, who is there? And look at the malignity with which he tries to fix it on some one else.' 'That may be because he is afraid of its being fixed upon him. Consider that point about the control of the letters. The business could only be done by some one through whose hands passed all the letters.' 'Checkley is the only person possible.' 'Yes; he understands that. It makes him horribly afraid. He therefore lies with all his might in order to pass on suspicion to another person. You and George think him guilty--well, I do not. If I were trying to find out the man, I should try a different plan altogether.' Her brother had work to do which took him out directly after an early breakfast. When Elsie was left alone, she began again to think about Mr. Dering's strange daylight somnambulism; about his continual fits of forgetfulness; about the odd things found on his table and in his safe, all connected with Edmund Gray. Checkley could not have placed those letters on the table: he could not have put those things in the safe.