Query: chapter books for 9 year old boys
The Hardy Boys Secret Files Collection Books 1-5: Trouble at the Arcade; The Missing Mitt; Mystery Map; Hopping Mad; A Monster of a Mystery (Hardy Boys: The Secret Files)
Trapped in a Video Game: The Complete Series
My Big Fat Zombie Goldfish Boxed Set: (My Big Fat Zombie Goldfish; The Seaquel; Fins of Fury)
Magic Tree House Boxed Set, Books 1-4: Dinosaurs Before Dark, The Knight at Dawn, Mummies in the Morning, and Pirates Past Noon
The Secret Lake: A children's mystery adventure