"Well, you are wonderful!" sighed Jess, sitting back on her heels. "I never would have thought of it in a century!"
"Oh, no!" laughed Corinne. "There's nothing wonderful about that. It's only common sense and puzzling it out like a riddle. Now see! If we take it for granted that the triangle means a space between the words, this sign of the dot between two triangles must be either the letter 'a,' 'I' or 'O,' for those are the only words of just one letter. But you can't tell which it is till you've puzzled out some more. And—after all, this idea may be all wrong. It may be something quite different, for all we know!"
"But what can it all be about?" began Jess, going off on another tack. "And how under the sun did the thing get hidden away in our old trunk under a false bottom. It's awfully mysterious!"
"Tell you what I think," volunteered Corinne. "Whatever it is, it's been in that trunk for years and years—hidden there, perhaps, when the trunk belonged to some one else. Do you know where it came from—the trunk, I mean?"
"No, I don't even know whether it was Father's or Mother's," answered Jess. "But I can ask Mother. Maybe she'd know."
"I'd like to puzzle this thing out!" mused Corinne. "Who knows! Perhaps we'd find it was something awfully interesting. It's simply full of mystery and—and possibilities!" At this point, Margaret, who during all the latter conversation had been fidgeting with impatience, began:
"Now, girls, look here! I've just had the most delightful idea! We've made the discovery of something awfully interesting, probably, if we could only find out what it's all about. Why not let's form ourselves into a secret society—just we four—with the purpose of finding out all about this mystery? We won't let another soul into the secret—not even Mother. Oh, it'll be such fun! Do, please!"
She looked imploringly at the twins, and for once they did not appear to object—even looked a trifle interested. For it was the ambition of Margaret's pitiful, limited little life to be the member of a "secret society." She had read much of school fraternities and clubs, and the fascinating idea had taken a firm root in her mind. Of course for her—poor helpless little invalid that she was—there could be no such thing as membership or participation in the real organizations. In place of this, she was forever begging her sisters to form a tiny society of their own, just the three, and have meetings and secrets and all the paraphernalia of the big school "frats."
But the idea had never appealed to the twins. They had no interest in any of the school clubs except the basket-ball and tennis teams. And to have a make-believe one at home with no earthly or apparent object was something they had never yet brought themselves to consider, much as they loved their invalid sister. But here was something a trifle different! Margaret, quick to see her advantage, hastened on: