Throughout the summer holidays after his first year at Hogwarts School of Witchcraft and Wizardry, Harry Potter has been receiving sinister warnings from a house-elf called Dobby.

Now, back at school to start his second year, Harry hears unintelligible whispers echoing through the corridors.

Before long the attacks begin: students are found as if turned to stone.

Dobby’s predictions seem to be coming true.