Agatha Christie's Poirot Season 10 Recap: All Four Mysteries and Their Killers Explained
Season 10 of Agatha Christie's Poirot trades the show's usual mix of shorter mysteries for four feature-length adaptations of some of Christie's most elaborate plots. Here's a recap of all four stories in order, and exactly who turns out to be responsible in each.
Season Recap: Four Feature-Length Mysteries
Season 10 breaks from the show's usual rhythm of shorter, stand-alone cases and instead commits to four full-length adaptations, each one built from an entire Christie novel rather than a shorter story stretched to fit the runtime. The season opens with The Mystery of the Blue Train, aboard the luxury service running from Calais to the French Riviera, where wealthy young Ruth Kettering is found strangled in her private compartment, her face disfigured and a valuable ruby missing from her belongings. Suspicion initially settles on her estranged husband, Derek Kettering, whose troubled marriage and financial motive make him the obvious target of the early investigation, but the real answer turns out to be considerably more calculated: Ruth's own maid, Ada Mason, strangles her in league with Major Knighton, who makes off with the ruby, while Mason poses as Ruth afterward to make it look as though the murder happened later than it actually did. The scheme almost works precisely because it exploits the assumption everyone makes early on, that a wife's estranged husband is the natural suspect, while the two people who actually staged the crime spend most of the investigation treated as background figures rather than anyone worth a second look.
Cards on the Table and After the Funeral
The season's second story, Cards on the Table, sets up one of Christie's most tightly constructed puzzles: the eccentric collector Mr. Shaitana invites four guests he privately suspects of having gotten away with murder to a dinner party alongside Poirot and three other investigators, all but daring the killers in the room to give themselves away. Shaitana is murdered during a game of bridge, and Poirot's solution depends entirely on reconstructing the hands played that night; Dr. Roberts turns out to be the killer, having used the one moment he was sitting out as dummy during a dramatic grand slam, when the other players were too absorbed in the game to notice him stab their host across the table.
After the Funeral follows immediately with another case built around impersonation. Cora Lansquenet is murdered with a hatchet shortly after suggesting, at her brother's funeral, that his recent death might not have been entirely natural. The killer is revealed to be Cora's own companion, Miss Gilchrist, who disguises herself as Cora earlier that day to build a false alibi before killing the real Cora for good, motivated by Cora's unwitting possession of a valuable painting and Miss Gilchrist's own desperation to reopen a tea shop she once ran.
Taken at the Flood and What Ties the Season Together
The season closes with Taken at the Flood, its most layered case: three deaths occur, but only one is a genuine, premeditated murder. Charles Trenton dies after a confrontation turns violent by accident, and Major Porter later takes his own life out of guilt over lying to the police, but the real killing is David Hunter poisoning Eileen Corrigan, the woman he had persuaded to impersonate his late sister Rosaleen in order to secure a fortune. Hunter kills her once he decides to marry Lynn Marchmont instead, eliminating the one person who could expose the whole scheme. It's a solution that only makes sense once Poirot establishes that the woman calling herself Rosaleen never actually was Rosaleen at all, which is why the case takes the form of an unusual denouement: rather than announcing a killer over a gathered group of suspects, Poirot arrives just in time to stop a second murder before it happens, and the fuller picture only comes together in the explanation afterward.
Taken together, the four mysteries of Season 10 all turn on the same basic trick: someone pretending to be someone else, whether briefly or for months at a time, in order to get away with a crime that would otherwise be immediately traceable back to them. Ada Mason poses as her murdered mistress, Miss Gilchrist poses as the woman she's about to kill, and Eileen Corrigan poses as a dead heiress right up until the moment that impersonation gets her killed too. Poirot's method across all four stories is essentially the same one applied four different ways: work out exactly who everyone actually is, and the killer stops being able to hide behind whoever they claimed to be.
Frequently Asked Questions
How many episodes are in Poirot Season 10?
Season 10 consists of four feature-length episodes: The Mystery of the Blue Train, Cards on the Table, After the Funeral, and Taken at the Flood, each adapted from a full Agatha Christie novel rather than a shorter story.
Who is murdered in The Mystery of the Blue Train?
Ruth Kettering, a wealthy young woman travelling on the luxury Blue Train to the French Riviera, is found strangled in her compartment, her face disfigured to delay identification, with a valuable ruby missing from her belongings.
Who killed Ruth Kettering, and how?
Ruth is strangled by her own maid, Ada Mason, working with Major Knighton, who steals the ruby and leaves the train while Mason, posing as her mistress, is deliberately seen aboard to make it look like Ruth was still alive after the murder actually took place.
Who is the initial suspect in the Blue Train murder?
Suspicion first falls on Ruth's estranged husband, Derek Kettering, who has both a strained marriage to Ruth and financial motive, and who admits he was aware of her presence on the train, making him the obvious focus of the early investigation before Poirot looks elsewhere.
Who is Mr. Shaitana in Cards on the Table, and why is he killed?
Shaitana is a wealthy, provocative host who invites four people he privately suspects of having gotten away with murder to a dinner party, alongside Poirot and three other detective figures, essentially daring the killers among his guests by hinting he knows their secrets.
Who killed Mr. Shaitana, and how was it done?
Dr. Roberts kills Shaitana during a bridge game, using a brief window while he's sitting out as dummy during a dramatic grand slam hand, when the other players are absorbed enough in the game not to notice him stab their host.
How does Poirot solve the Shaitana murder?
Poirot reconstructs the bridge game itself hand by hand, working out exactly who was distracted, who was dummy, and when, and realizes the murder could only have been carried out during the one moment Dr. Roberts was free to move around the table unnoticed.
Who is murdered in After the Funeral, and who did it?
Cora Lansquenet is murdered with a hatchet after voicing suspicion, at her brother's funeral, that his recent death might not have been natural. The killer is Miss Gilchrist, Cora's own companion, who disguises herself as Cora to establish a false alibi before killing her for real.
Why does Miss Gilchrist kill Cora in After the Funeral?
Cora has unknowingly come into possession of a valuable painting, and Miss Gilchrist, desperate for money to reopen a tea shop she once ran, kills her both to plant the idea that the earlier death was murder and to gain access to the painting for herself.
How many people actually die in Taken at the Flood?
Three deaths occur, though only one is a deliberate murder: Charles Trenton dies after a fight goes wrong, Major Porter dies by suicide out of guilt, and Eileen Corrigan, posing as Rosaleen Cloade, is the only victim of a genuine, premeditated killing.
Who is the real killer in Taken at the Flood?
David Hunter poisons Eileen Corrigan, the woman he had persuaded to pose as his sister Rosaleen after the real Rosaleen died, murdering her to eliminate his accomplice once he decides to marry Lynn Marchmont, the woman he genuinely loves, instead.
What connects all four mysteries across Season 10?
Each story hinges on a false identity or a staged appearance: a maid impersonating her murdered mistress, a companion impersonating the woman she's about to kill, and an accomplice impersonating a dead heiress, with Poirot's method in every case built around exposing exactly who someone is pretending to be.