6. In which Christie novel, featuring Hercule Poirot, does a demure live-in companion take a hatchet to her elderly employer so that she can obtain enough money to open a tea shop?
From Quiz Motive for Murder
Answer:
After the Funeral (U.S. title "Funerals are Fatal")
The culprit here is the genteel Miss Gilchrist, an amateur painter, and very knowledgeable about art. For years she suffered in silence as her elderly employer, the foolish, garrulous Cora Lansquenet (herself the widow of an artist, whom she married against her wealthy family's wishes) prattled on about art and bought perfectly worthless daubs at local shows. Then, one day, Cora purchased a rare Vermeer, not realizing its value. Miss Gilchrist, who never ceased mourning the loss of her tea shop during the war saw an opportunity to finance another such venture by selling the painting; but she had to get rid of Cora first. When Cora's brother, Richard Abernathy, dies suddenly, Miss Gilchrist drugs Cora, dons her clothes, jewelry, and hairpiece, and impersonates her at the funeral supper, where most of the family haven't seen the real Cora in ages, if at all. There she drops a typically Cora-like bombshell about Richard having been murdered. She then returns home and bashes Cora's face in with a hatchet.
As a result of the bombshell at the funeral supper, it's assumed that Richard's murderer also did away with Cora, fearing exposure. Poirot, however, is not deceived; a few small details, such as a recently made oil painting, a bouquet of wax flowers, and a nun, (seen only by Miss Gilchrist) pique his interest. When an autopsy on Richard Abernathy reveals nothing untoward, Poirot fits the pieces together and exposes Miss Gilchrist. She is taken to prison, where she goes mercifully potty and makes demented plans for a tea shop franchise.