'Keep calm, dear," Miss Harmony said. 'Once you have been given the key and you touched it, it remains yours and yours alone. This key was given to you, dear. And it knows it belongs to you, so if you lose it, it will find you wherever you are, when you want to enter any of the rooms of the main building and those near Elmbridge School of Magic, where you are allowed. It will be in your possession all the time and will help you get where you want."

The woman saw that Elizabeth didn't ...