"Why, no!" exclaimed Doris, struck with the new idea. "I never thought of it as anything he might have left for _her_. Do you remember, she said once they were awfully fond of each other, more even than most brothers and sisters? It would be perfectly natural if he _did_ want to leave her a note, if he had to go away and perhaps never come back. And of course he wouldn't want any one else to understand what it said. Oh, wait!--I have an idea we've never thought of before. Why on earth have we been so _stupid_!--" She sprang up and began to walk about excitedly, while Sally watched her, consumed with curiosity. At length she could bear the suspense no longer. "Well, for pity's sake tell me what you've thought of!" she demanded. "I'll go wild if you keep it to yourself much longer." "Where's that copy?" was all Doris would reply. "I want to study it a moment." Sally drew it from her pocket and handed it to her, and Doris spent another five minutes regarding it absorbedly. "It is. It surely is!" she muttered, half to herself. "But how are we ever going to think out how to work it?" At last she turned to the impatient Sally. "I'm a fool not to have thought of this before, Sally. I read a book once,--I can't think what it was now, but it was some detective story,--where there was something just a little like this. Not that it looked like this, but the idea was the same. If it is what I think, it isn't the note itself at all. The note, if there is one, must be somewhere else. This is only a secret _code_, or arrangement of the letters, so that one can read the note by it. Probably the real note is written in such a way that it could never be understood at all without this. Do you understand?" Sally had indeed grasped the idea and was wildly excited by it. "Oh, Doris," she cried admiringly. "You certainly _are_ a wonder to have thought all this out! It's ten times as interesting as what we first thought it was. But how do you work this code? I can't make anything out of it at all." "Well, neither can I, I'll have to admit. But here's what I _think_. If we could see what that note itself looks like, we could perhaps manage to puzzle out just how this code works." "But how are we going to do that?" demanded Doris. "Only Miss Camilla has the note, if there _is_ a _note_, and certainly we couldn't very well ask her to let us see it, especially after what she said to us that day." "No, we couldn't, I suppose," said Doris, thoughtfully. "And yet--" she hesitated. "I somehow feel perfectly certain that Miss Camilla doesn't know the meaning of all this yet, hasn't even guessed what we have, about this paper. She doesn't act so. Maybe she doesn't even know there _is_ a note,--you can't tell. If she hasn't guessed, it would be a mercy to tell her, wouldn't it?" "Yes, I suppose so," admitted Sally dubiously. "But I wouldn't know how to go about it. Would you?"