Ruby Baker

 was a student at the Saxon Heights boarding school, when had become a temporary head in 2016. She had been forced to wear a uniform resembling Missy's costume, and had to give away all of her mobile communication devices, for Missy's plan to summon a Dæmon. However, Osgood realised Missy's plan and ordered UNIT to stop her, saving Ruby from almost being killed by Missy. (PROSE: Yes, Missy)