Saxon Heights was a school.
Missy became a headteacher there after she had done away with the previous one, Mrs Goss. She had implemented new and strange rules, such as a school uniform that was almost identical to her own clothing, and getting rid of everyone's mobile communication devices, with her excuse being that they were used too often. However, the real reason was that because she wanted to summon up a Dæmon by hooking up her newly acquired devices to a transmitter. The Osgoods found this out and had UNIT stop her, although she managed to escape. (PROSE: Yes, Missy)