Missy has been imprisoned in the vault for some time, nobody has visited her in six months and she's bored. So when the Doctor and Bill come to ask her for help, Missy can't resist having a little fun with them - and she has some demands. But she has promised to be good and she's trying hard to be good, If only the Doctor really appreciated how much she's changed. If only he believed her tears at remembering the things she's done and the people she's killed.