91 books • 20 series
Book #11: The Haunted Tower
Book #15: Journey to the Lost Temple
Book #1: A Horse for the Summer
Book #2: Runaway Pony
Book #3: Strangers at the Stable
Book #4: The Midnight Horse
Book #5: Dream Pony
Book #7: Puzzle Dungeon
Book #9: Puzzle Train
Book #10: Puzzle Ocean
Book #11: Puzzle School
Book #12: Puzzle Holiday