I read Harry Potter and the Chamber of Secrets by J.K.Rowling. In this book Harry has adventures in his second year at Hogwarts, his school.
In this book Harry meets a house elf, goes to a Death Day party, and tons of other stuff, but then something strange is going on! Everyone is being found petrified, even one of Harry's friends! Then something outstandingly weird happens to Harry because of his crazy Defense Against the Dark Arts teacher, Gilderoy Lockhart!
I really like this book because of all the adventure and mystery. If you like mystery I also recommend the Nancy Drew and the Clue Crew series.