Challenge for the Chalet School #987182

The Head finished speaking. Her three listeners sat on in frozen silence for the moment. They could scarcely believe their ears. Finally Margot, youngest of the Maynard triplets, broke it. She was usually the one first off the mark.
“Auntie Hilda, do you really mean that?” she asked incredulously.
Miss Annersley nodded, “I do.”
“But—but what’s to become of us—the school, I mean?”
“You will go on as usual,” Miss Annersley said briskly. “What else did you suppose, Margot?”
Margot subsided and Len, the eldest of the three, took up the tale. “Who will be Head while you are away? Is Auntie Nell coming here to take over?”
“She most certainly is not. She can’t be spared from St Mildred’s—they’re going to be short-handed as it is for the first half of the term. She’ll come for her usual science lessons with the two sixth forms, but apart from that she won’t be able to manage anything.”
“St Mildred’s short?” Margot exclaimed. “Why what’s happened? Who’s gone?”