67 books • 7 series
Book #2: Labyrinth of Fire
Book #5: Roads of Madness
Book #6: Chamber of Ghosts
Book #7: Valley of Monsters
Book #8: Prison of Despair
Book #1: Unicorn Rescue
Book #1: Unicorn Hunters
Book #2: Sinister Roots
Book #3: Gargoyle Scourge
Book #4: Haunted Fortress
Book #25: Spectroscopy
Book #2: Robot Blood
Book #3: Caleb's World
Book #4: Warp Giants
Book #5: Aliens Undead