25 books - 1 hardcover the rest are paperback • (Hardcover) The Hunt for the Hundredth Key • The Chocolate Chase • The Invisible Thief • The Stone of Fire • Cyber-Thief Showdown • Flood Mission • The Smelly Search • Attack of the Dragons • The Perilous Plants • Magical Mission • Dinosaur Danger • Stay Strong, Geronimo! • Away in a Star Sled • Charge of the Clones • Insect Invasion • A Cheese Colored Camper • Pull The Dragons Tooth! • Pirate Spacecat Attack • The Dragon Crown • Mice To The Rescue • Slurp Monster Showdown • The Mysterious Message • The Cheese Experiment • Robot Attack • The Famous Fjord Race