nthia
looked up with a frown, from an irregular Latin conjugation.

"What's a _theory_?"

"Why, you know! In Conan Doyle's mystery stories _Sherlock Holmes_
always has a 'theory' about what has happened, before he really knows;
that is, he makes up a story of his own, from the few things he has
found out, before he gets at the whole truth."

"Well," replied Cynthia, laying aside her Latin grammar, "since you ask
me, my theory is that some one committed a murder in that room we can't
get in, then locked it up and went away, and had the house all boarded
up so it wouldn't be discovered. I've lain awake nights thinking of it.
And I'd just as lief _not_ get into that room, if it's so!"

Joyce broke into a peal of laughter. "Oh, Cynthia! If that isn't exactly
like you! Who but you would have thought of such a thing!"

"I don't see anything queer about it," retorted Cynthia. "Doesn't
everything point that way?"

"Certainly not, Cynthia Sprague! Do you suppose that even years and
years ago any one in a big house like this could commit a murder, and
then calmly lock up and walk away, and the matter never be investigated?
That's absurd! The murdered person would be missed and people would
wonder why the place was left like this, and the--the authorities would
get in here in a hurry. No, there wasn't any murder or anything
bloodthirsty at all; something very different."

"Well, since you don't like _my_ theory," replied Cynthia, still
nettled, "what's yours? Of course you _have_ one!"

"Yes, I have one, and I have lain awake nights, too, thinking it out.
I'll tell you what it is, and if you don't agree with me, you're free to
say so. Here's the way it all seems to me:

"Whatever happened in that house must have concerned two persons, at
least. And one of them, you must admit, was our Lovely Lady whose
portrait hangs in the library. Her room and clothes and locket show
that. She looks very young, but she must have been some one of
importance in the house, probably the mistress, or she wouldn't have
occupied the biggest bedroom and had her picture on the wall. You think
that much is all right, don't you?" Cynthia nodded.

"Then there's some one else. That one we don't know anything at all
about, but it isn't hard to guess that it was the person whose picture
is turned to the wall, and whose miniature was in the locket, and who,
probably, occupied the locked-up room. That person must have been some
near and dear relation