I'll have to look up this Miss Peregrine thing for DD!
I would recommend the Mysterious Benedict Society (5.6 to 6.3) books, if he hasn't already read them.
Also Simon Bloom, Gravity Keeper (it's a 4.9 but Simon is a 6th grader and I wouldn't count it out for older, as it's fascinating science-magic) and Simon Bloom, The Octopus Effect (5.3).
The Artemis Fowl books are terrific -- they're 4.something to 6.something.
John Grisham's Theodore Boone, Kid Lawyer books are good, 5.somethings. I think Artemis Fowl is considerably more complex than those, so I'm not sure how they rate things.
