47 books • 19 series
Book #7: Danger at Demon's Cove
Book #10: The Ghost in the Mirror
Book #12: Agent Arthur's Arctic Adventure
Book #13: Ghost Puzzle Adventures
Book #14: Search for the Sunken City
Book #1: Escape from Blood Castle
Book #2: Curse of the Lost Idol
Book #4: Incredible Dinosaur Expedition
Book #5: The Intergalactic Bus Trip
Book #6: Time Train to Ancient Rome