In the short story The Case of the Caretaker, Mrs Murgatroyd is a character in a manuscript written by Dr Haydock. In the story, she is a widow, and her husband has been dead for two years. She and her husband had been the caretakers at Kingsdean House, and had been there for nearly thirty years.
Mrs Murgatroyd is described as having a "cunning, dark gypsy face, with wisps of iron-grey hair, and bleared, suspicious eyes".
Mrs Murgatroyd continues to hang around near Kingsdean House, and shouts at Harry and Louise Laxton. Louise thinks that she cursed them.
According to Harry, Mrs Murgatroyd resented the house being pulled down, and she had gone "a bit queer" after her husband's death. When Louise asks her what she wants, Mrs Murgatroyd says that she wants her own place in Kingsdean House, and that Harry turning her out will bring him bad luck. She tells Louise that there will be no happiness for them in the house, only sorrow, death, and her curse.
Harry arranges for Mrs Murgatroyd to go out to America, where she has a son, and offers to pay her passage. However, before that can happen, Mrs Murgatroyd startles Louise's horse, Prince Hal, causing him to throw Louise off, killing her. Mrs Murgatroyd then left the area, and went to Liverpool, to await the boat that would take her to America.
It is later revealed that someone had paid Mrs Murgatroyd to utter curses at Harry and Louise, and to startle Louise's horse, causing the accident.