In the novel The Mystery of the Blue Train, Katherine Grey is the former companion to Mrs Harfield, to whom the other’s wealth is left in her will. She travelled on Le Train Bleu to the French Riviera. Katherine is a cousin of Rosalie Tamplin, which lives in Villa Marguerite. She is one of the Worcestershire Greys.
She lives in St. Mary Mead in Kent, but hails from Edgeworth in Worcestershire.
Katherine is thirty-three years old. She had come from a good family, but her father had lost all his money, and she had to work for a living from a young age. When she was twenty-three, she started working as Mrs Harfield's companion. At that time, she was a "quiet girl with beautiful eyes". At present, she is a quiet woman, with the same beautiful grey eyes. Her eyes are described as "shining steadily out on the world with a kind of happy serenity", which nothing can shake. She has a sense of humour, with which she was born.
Katherine receives a letter from Mrs Harfield's relations, saying that Mrs Harfield's mind had been failing, and that the will leaving her money to Katherine will not hold good in court. Dr Harrison is of the opinion that this is an odious letter, but Katherine says that it is quite natural under the circumstances.
Katherine is a sympathetic listener, having listened to Mrs Harfield for ten years. She would listen with half her mind, and say the right things mechanically when Mrs Harfield paused. Even after Mrs Harfield's death, Katherine is still in the habit of listening, and is able to listen sympathetically to Mrs Harrison, and later, Ruth Kettering.
Katherine is of the opinion that being physically tied to St. Mary Mead gave her a lot of mental freedom. However, she feels that she wants a change, and to "be in the midst of things", even as a looker-on.
When Katherine leaves St. Mary Mead, half the village comes to see her off at the station, including Alice, the maid of all work. According to Alice, Katherine was particular about the brasses and the dust, but would always notice when Alice gave a thing an extra rub when cleaning it. Katherine was also very kind when Charlie left Alice for a girl who worked at the dairy.
Katherine meets Ruth Kettering on the Blue Train, and Ruth tells her that she is going to Paris to meet the Comte de la Roche, but feels bad about deceiving her father. Katherine tells her that she could send her father a wire from Paris, and he would come to her.
After Ruth is found dead, Katherine is interviewed by Commissary Caux. She tells him and Poirot about the conversation she had with Ruth. She is also asked to identify the body.
Katherine has good nerves, and is able to look "long and earnestly" at the body. Even though the face is disfigured, Katherine is able to identify Ruth because she observes that the build, carriage, and hair are exact, and she had also noticed a small mole on Ruth's wrist while she was talking to her.
While in Nice, Katherine stays at the Villa Marguerite, with Lady Tamplin and her family. She does not enjoy Lady Tamplin's "remorseless cross-examination" about the murder, and refuses to publish an article about it. She becomes friends with Lady Tamplin's daughter, Lenox, with whom she shares a common interest in clothes.
Katherine later goes to meet Rufus Van Aldin at his hotel. She tells him about her conversation with Ruth on the Blue Train. Van Aldin later invites her to the tennis, and sends Major Knighton to call for her innthe car.
Katherine later goes to Monte Carlo with Lady Tamplin, and they run into Poirot and Major Knighton there. Katherine senses that Poirot is trying to convey something to her, but she tells him that she is not clever at taking hints, and asks him to say whatever it is directly. She feels that Poirot is trying to warn her against someone, but does not know who. Later, when she is alone, Katherine feels that Ruth Kettering is standing beside her, trying to tell her something, but she does not know what.
Katherine receives a letter from Miss Viner, telling her that if things should go poorly, there will always be a home for her in St. Mary Mead. This makes her realise that St. Mary Mead is still home, and she decides to go back.
Katherine becomes a companion to Miss Viner in St. Mary Mead. While going through Miss Viner's collection of newspaper clippings, she finds an article about a jewel robbery at Lady Tamplin's house, which took place when the house was used as an Officers' Hospital during the War. She later shows it to Poirot, who tells her that it shows a different angle to the case, but that the ideas are the same.
Portrayals[]
Agatha Christie's Poirot[]
In the "The Mystery of The Blue Train" episode of Agatha Christie's Poirot, Katherine Grey was portrayed by Georgina Rylance. Here a subplot is added in which Rufus Van Aldin had led Katherine's father to suicide. This was probably made up so that she had a valid motive for killing his daughter.
At the end of the episode, Katherine says she discovered to be very fond of traveling, and said that she would have boarded the Orient Express at Vienna. This could be an allusion to the events of Murder on the Orient Express (note that, in Murder on the Orient Express, Katherine Grey does not appear, nor she does in any adaptation of the novel). In the original The Mystery of the Blue Train, there is a different connection between the two novels. The attendant of Le Train Bleu is named Pierre Michel, just like the one on Murder on the Orient Express. For more information about the two characters, visit this page.