“‘Mem. Read in this order--Midsummer Night’s Dream.’ That sounds good for a beginning,” she said to herself. “I just love the name of it. I wonder what it’s about?” Running to the bookshelves on the left side of the fireplace, where one whole section was devoted to the works of William Shakespeare, Mary began fumbling among the little red books. “Here is ‘A Midsummer Night’s Dream’!” said she, settling herself in the big leather armchair to read. “Why, it’s full of fairies and private theatricals! I know it is going to be nice!” Mary read for some time and found that she liked the play even better than she had expected. She always liked to read about fairies, of whom, indeed, the book was full. And the scene of the play-acting was very funny, she thought, especially where Bottom wanted to play all the parts himself. Presently she came to a place in the text where a line was heavily underscored. It was where Moon says, “_This lantern is my lantern_.” “I wonder why Aunt Nan marked that line?” thought Mary. She turned to see if there was anything about a lantern in the notes. And there she found this remark in the writing which she had come to recognize as Aunt Nan’s: “_See lantern on mantelshelf._ CAREFUL!” “That is a funny note!” thought Mary. “What mantelshelf? There isn’t any in the play. Can she mean--why, yes! There’s a lantern over there on _my_ mantelshelf!” Sure enough! Mary had not noticed it especially until this minute. But there, not far from the bust of Shakespeare, was a queer old tin lantern, pierced with holes for a candle to shine through--the very kind that Moon must have used in the play, in Shakespeare’s day. Mary dropped the book and went over to the lantern, with a pleasant sense of possession. Everything in the room was hers. This would be just the thing to play Pyramus and Thisbe with! She took up the old lantern and examined it curiously. In the socket was the stub of a candle. “I wonder who lighted it last?” thought Mary idly. She tried to pull out the candle, but it stuck. She pulled harder, and presently--out it came! There was something in the socket below--something that rattled. Mary shook the lantern and out fell a tiny key; a gilt key with a green silk string tied to the top. That was all. “What a funny place for a key!” thought Mary. “I wonder how it got there.” Then she thought again of the quotation which had been underlined--“‘_This lantern is my lantern_.’ She wanted me to find it, I am sure!” thought Mary eagerly. “It is the key to something. Oh, if I could only find what that is! How in the world shall I know where to look?” “Oh, John!” she cried, “John!”--for just then she heard his whistle in the hall, and she ran down to show him her find. Up came John; up the stairs two steps at a time, with Mary close after him. “I bet I know what it is!” he cried. “It’s the key to a Secret Panel. I’ve read about them in books, lots of times. Let’s hunt till we find the keyhole.”