Horror House (Mary Hooper's Haunted)

A new couple have moved into Hardstone House and it's just Jake's luck that instead of a cool, footballing grandson they have a granddaughter called Claire, who likes tap-dancing and tea parties. But then Claire tells Jake and Jenna that Hardstone House was once a school, with a cruel and heartless headmaster, and she reckons it's haunted. But by whom? And why...?