Harry Potter and the Chamber of Secrets by J. K. Rowling
Harry can't wait for his holidays with the dire Dursleys to end. But a small, self-punishing house-elf warns Harry of mortal danger awaiting him at Hogwarts School. Returning to the castle nevertheless, Harry hears a rumour about a chamber of secrets, holding unknown horrors to magicians of Muggle parentage. Now someone is casting spells that turn people to stone, and a terrible warning is found painted on the wall. The chief suspect - who's always in the wrong place - is Harry. But something much darker has yet to be unleashed.