Zia loved the old library in her town. One rainy day, she sat on a soft chair and read a book about stars. She saw pictures of constellations, which are groups of stars that make shapes in the sky. Zia noticed a tiny pencil mark on the page. She looked under the table and found a small note. The note said, "Look in the blue book."
The next day, Zia went back to the library. She found the blue book on a high shelf. Inside the book, she saw a map of the library. The map showed a secret room behind the wall. Zia felt curious and a little scared. She walked to the wall and touched it. Then she saw tiny footprints on the floor. The footprints were small and dusty. They went across the room and stopped in the middle of nowhere.