22 books • 3 series
Book #1: The Magic Sapphire
Book #2: The Lady Ghost
Book #4: The Mysterious Music Box
Book #5: The Statue of Anubis
Book #1: Problems in Prague
Book #2: Jeopardy in Geneva
Book #3: Bedlam in Berlin
Book #4: Danger in Dublin
Book #1: El Zafiro Mágico
Book #2: La Dama Fantasma