Annabel Greystone

 the daughter of Lord Geoffrey Greystone and Lady Edith Greystone. Her mother died in 1906.

Annabel made the acquaintance of the Marquis of Rostock, in reality the alien Roztoq, without her father's awareness. When the First Doctor made Lord Greystone aware of this fact, Lord Greystone invited the Doctor and "Rostock" to his house so the Doctor could confront Roztoq.

Roztoq brought a small silver thing that he threw at Annabel. It possessed her, though she was aware of what was happening. Under the alien's control, she entered the servants' hall. Mrs Doyle, the cook, was in hysterics because the butler, Mr Golightly, had just died. Annabel found herself wishing that Mrs Doyle would stop screaming, and the alien shut Mrs Doyle up for good. The Doctor entered, and encouraged Annabel to fight the possession. She did so, and the alien left her. (PROSE: 64 Carlysle Street)