My 7yo has really enjoyed the Secret Seven and Five Find Outer books by Enid Blyton - even though they are a bit old-fashioned. Can anyone recommend similar mystery books? I think Famous Five are a bit older/harder to understand at the moment.
Preferably ones that aren't full of kids calling people names or ker-aaaazy /streetwise stuff - nice and gentle is more his style! He's also read and loved the 13 Storey Treehouse series (they are crazy but not mean).