The curse of the ancient mask and other case files - Simon Cheshire

Saxby Smart is a schoolboy detective. His Crime HQ may be a battered garden shed, but his sleuthing skills are first-rate - which is just as well, since no one else can solve the baffling mysteries he's called on to decipher.
In this book, Saxby reveals three mind-twisting mysteries - an ancient mask that brings nothing but bad luck for its owner, strange acts of sabotage causing chaos at school, and the theft of a valuable brooch, which could spell big trouble for Saxby's friend.
Contained within the stories are the clues to crack the cases - but are you 'smart' enough to solve them like Saxby?