50 books • 11 series
Book #15: Origin Unknown 15
Book #19: Origin Unknown 19
Book #16: Origin Unknown 16
Book #17: Origin Unknown 17
Book #1: Fair Games 1
Book #23: Origin Unknown 23
Book #4: Origin Unknown IV
Book #20: Origin Unknown 20
Book #21: Origin Unknown 21
Book #2: Origin Unknown II
Book #3: Origin Unknown III
Book #5: Origin Unknown V
Book #6: Origin Unknown VI
Book #7: Origin Unknown VII
Book #11: Origin Unknown 11