# Ruth Kettering — The Mystery of the Blue Train character guide > Ruth Kettering in The Mystery of the Blue Train by Agatha Christie. **Role:** major **Also known as:** Ruthie, Ruth Van Aldin, Mrs. Kettering **First appearance:** 0005-iv-in-curzon-street ## Snapshot A millionaire's daughter trapped between a reckless husband and a dangerous lover, she boards the Blue Train with a secret she never gets to tell. ## Who they are Ruth Kettering is the pivot on which the whole tragedy turns: rich, restless, and quietly desperate to escape a marriage her father is determined to end for her. She confides in a stranger, Katherine Grey, about a man she is going to meet and a decision she has finally reached, and that conversation becomes the last clear window into her mind. Her father adores her; her husband resents her; her lover may want more than her affection. Her choices in the hours before the murder define everything Poirot must untangle. ## Relationships ### [Hercule Poirot](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/hercule_poirot) _professional_ Poirot investigates Ruth's murder, interacting with her primarily through clues and witness accounts. ### [Katherine Grey](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/katherine_grey) _social_ Katherine meets Ruth on the train and has polite but brief interactions before Ruth's murder. ### [Major Knighton](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/major_knighton) _professional_ Knighton serves as Ruth's secretary and confidant, handling her affairs with loyalty. ### [Derek Kettering](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/derek_kettering) _family_ Derek and Ruth are estranged married couple, with deep resentment and financial conflicts. ### [Comte de la Roche](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/comte_de_la_roche) _romantic_ The Comte is Ruth's lover, but his motives are largely financial and manipulative. ### [Hercule Poirot](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/hercule_poirot) _professional_ Poirot investigates Ruth's murder, interacting with her primarily through clues and witness accounts. ### [Derek Kettering](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/derek_kettering) _family_ Derek and Ruth are estranged married couple, with deep resentment and financial conflicts. ### [Hercule Poirot](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/hercule_poirot) _professional_ Poirot investigates Ruth's murder, interacting with her primarily through clues and witness accounts. ### [Major Knighton](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/major_knighton) _professional_ Knighton serves as Ruth's secretary and confidant, handling her affairs with loyalty. ### [Comte de la Roche](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/comte_de_la_roche) _romantic_ The Comte is Ruth's lover, but his motives are largely financial and manipulative. ### [Katherine Grey](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/katherine_grey) _social_ Katherine meets Ruth on the train and has polite but brief interactions before Ruth's murder. ### [Major Knighton](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/major_knighton) _professional_ Knighton serves as Ruth's secretary and confidant, handling her affairs with loyalty. ## In the story ### [The Mystery of the Blue Train](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/the-mystery-of-the-blue-train) Introduced as a wealthy and unhappy woman traveling on the Blue Train, central to the unfolding mystery. ### [Heart of Fire](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/iii-heart-of-fire) Mentioned as having telephoned and written to her father; her letter upsets Van Aldin. ### [In Curzon Street](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/iv-in-curzon-street) Receives her father in Curzon Street, discusses her unhappy marriage and Derek's affair with Mirelle, agrees to divorce, and receives the ruby necklace. ### [A Useful Gentleman](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/v-a-useful-gentleman) Mentioned as the daughter seeking divorce; later meets with Van Aldin but deflects his questions about Derek's insinuations. ### [VI: Mirelle](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/vi-mirelle) Discussed as the target of divorce proceedings; Mirelle hints at her past with the Comte de la Roche. ### [X: On the Blue Train](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/x-on-the-blue-train) Travels on the Blue Train, deeply conflicted and panic-stricken about her decision; confides in Katherine Grey. ### [XI: Murder](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xi-murder) The murdered woman; found strangled with a black cord, her face disfigured after death; identified by Katherine via a mole on her wrist. ### [Van Aldin Gets a Telegram](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xiii-van-aldin-gets-a-telegram) Mentioned as having sent her maid to the Ritz in Paris; later reported murdered and robbed on the Riviera. ### [XIV: Ada Mason's Story](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xiv-ada-mason-s-story) Discussed through Mason's testimony; revealed to have carried the valuable rubies against her father's advice. ### [The Comte de la Roche](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xv-the-comte-de-la-roche) Mentioned as having resumed her acquaintance with the Comte and planning to meet him; her murder is under investigation. ### [XVI: Poirot Discusses the Case](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xvi-poirot-discusses-the-case) The victim; her divorce plans and financial settlement are central to the discussion. ### [M. Papopolous Breakfasts](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xxii-m-papopolous-breakfasts) Her murder and the theft of her rubies are the subject of Poirot's inquiry with Papopolous. ### [A New Theory](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xxiii-a-new-theory) Referenced as the victim; the cigarette case she bought for Derek is discussed. ### [A Warning](https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/chapters/xxvi-a-warning) Katherine senses the spirit of Ruth Kettering standing beside her, trying to convey something of vital importance. ## Links - HTML: https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters/ruth_kettering - Book: https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se - All characters: https://www.betterreads.dev/discover/the_mystery_of_the_blue_train_se/characters