You will find that this activity book has a good balance of easy and hard puzzles.
A to Z Mysteries Ser.
LOT OF 20 A TO Z MYSTERIES CHAPTER BOOKS Mixed Lot AGES 6-9 Paperback
A nice touch is the illustrated author bio at the very end.
LOT OF 25 A TO Z MYSTERIES CHAPTER BOOKS Mixed Lot AGES 6-9 Paperback
The book is illustrated with pen-and-ink drawings that feel raw.
The Kidnapped King; A to Z Mysteries – paperback, 9780679894599, Ron Roy
A nice touch is the illustrated thank you page from the creator.
A TO Z Mysteries The Goose’s Gold 2002 Trade Paperback)
The book is illustrated with vintage prints that evoke nostalgia.