Peggy flew, only too glad to get away from the black, yawning hole. She was back in three minutes with the lamp, and the three cousins peered into the open space, Margaret holding the lamp high above her head, so that the light might penetrate as far as possible.

It was indeed a staircase; a narrow, winding way, wide enough for one person, but no more. It plunged down like a black pit, and its end could not be seen.

"But this is superb!" cried Margaret. "Shall we explore it, girls? I don't suppose there can be any objection, do you? It is probably never used."

"By all means, let us explore!" said Rita. "But do you know what I am thinking, Marguerite?"

"Something romantic and mysterious, I am sure!" said Margaret, smiling.

"Something practical and businesslike, rather, très chère. I am thinking that for a concealment, if a concealment were necessary, this is the finest house in the world. Come on!"

Peggy hung back, her round cheeks pale with dread; but she could not bear to be left behind; and as Margaret and Rita plunged down the narrow stair, she followed, with beating heart. She had longed all her breezy little life for mystery, adventure, something wonderful to happen to her, with which she could impress and awe the younger children; now it had really come, and her heart beat with mingled terror and excitement.

Down—down—down. The lamplight shone on the rough walls of discoloured plaster, the old steps creaked beneath their tread; that was all. Now they came to a tiny landing, and something gleamed before them,—the brass handle of a door. Margaret hesitated, fearing that they might be trenching on forbidden ground; but Rita opened the door quickly, and Peggy pressed down behind her.

They saw a room, like the other bedrooms in the house, large and airy. It was evidently ready for use, the bed neatly made, everything in spotless order. Brushes and shaving-tools lay on the dressing-bureau. The table was covered with books.

"Uncle John's room!" whispered Margaret. "It must be, of course; and this is where the locked door is on the second story. Come along, girls; we ought not to go prying into people's rooms!"