"I have it!" cried Joyce, at length. "At least, I think this may be an explanation. That's a small door, without a doubt,—perhaps to some unused closet. Maybe there was a time, when this house was new, when this room wasn't a library. Then somebody wanted to make it into a library, and fill all this side of the room with book-shelves. But that door was in the way. So they had it all papered over, and just put the shelves in front of it, as though it had never been there. You see the paper has fallen away, probably through dampness,—and the mice seem to have eaten it too. And here's the keyhole! Isn't it lucky we just happened to take the books out that were in front of it!"
"But what are we going to do about it?" questioned Cynthia.
"Do? Why, there's just one thing to do, and that is move the shelves out somehow,—they seem to be movable, just resting on those end-supports,—and get at that door!"
"But suppose it's locked?"
"We'll have to take a chance on that! Come on! We can't move these books and shelves away fast enough to suit me!"
They fell to work with a zest the like of which they had not known since their first entrance into the Boarded-up House. It was no easy task to remove the armfuls of books necessary to get at the door behind, and then push and shove and struggle with the dusty shelves. In a comparatively short time, however, the floor behind them was littered with volumes hastily deposited, and the shelves for a space nearly as high as their heads were removed. Then they tore at the mouldy shreds of wall-paper till the entire frame of the paneled wooden doorway was free. Handle there was none, it having doubtless been removed when the place was papered. There seemed, consequently, no way to open the door. But Cynthia was equal to this emergency.
"I've seen an old chisel in the kitchen. We might pry it open with that," she suggested.
"Go and get it!" commanded Joyce, bursting with excitement. "I think this is going to be either a secret cupboard or room!"
Cynthia seized a candle and hurried away, coming back breathless with the rusty tool.
"Now for it!" muttered Joyce. She grasped the chisel and inserted it in the crack, pushing on it with all her might. But the door resisted, and Cynthia was just uttering the despairing cry,—