Ruby Baker

 was a student at the Saxon Heights boarding school, when had become a temporary head. She had been forced to wear a uniform resembeling Missy's costume, and had to give away all of her mobile communication devices, for her plan to summon a Dæmon. However Osgood has realised her plan and ordered UNIT to stop her, saving her from almost being killed by Missy. (TV: Yes, Missy)