434 books • 56 series
Book #1: The Fourth Floor Twins and the Fish Snitch Mystery
Book #2: The Fourth Floor Twins and the Fortune Cookie Chase
Book #4: The Fourth Floor Twins and the Silver Ghost Express
Book #1: Don't Throw It to Mo!
Book #2: Get a Hit, Mo!
Book #3: Pass the Ball, Mo!
Book #4: Kick It, Mo!
Book #7: Spike It, Mo!
Book #5: Bones and the Birthday Mystery
Book #6: Bones and the Math Test Mystery
Book #7: Bones and the Roller Coaster Mystery
Book #8: Bones and the Clown Mix-Up Mystery