Katie O'Conner doesn't realize that her habit of questioning everything annoys adults. But when Katie finds a secret library, along with her three friends and little brother, she finally finds some answers to her questions. The problem is that seven evil Enemies of the Library and their Dark Master are trying to take over the world. Can Katie, her friends, her brother and the Library's caretaker, defeat them? 1. The Library Kids Mystery of the Blue Mounds2. The Library Kids The Serpent of Rock Lake3. The Library Kids Cry of the Banshee4. The Library Kids Talking Stones5. The Library Kids Princess of Tara6. The Library Kids The Pharaoh's Clue7. The Library Kids House of the Dragon