Lady Athelinda Playford, author of a popular series of children's mystery novels, summons her children, lawyers, and Poirot and Edward Catchpool, Scotland Yard detective, to her home in Clonakilty, Ireland, where she plans to announce a change to her will that may shock those closest to her: she intends to leave everything to her secretary, a man with only weeks to live due to a terminal illness, cutting out her son and daughter completely.
Poirot begins to suspect that he and Catchpool have been invited to prevent a murder, but despite their efforts one of the party is killed, and not the one they were expecting. Poirot and Catchpool must disentangle the truth from a rat's nest of bitter family resentments, in a family where almost everyone seems to despise each other.
Upstairs (family and guests)
- Hercule Poirot, retired Belgian policeman turned private investigator, invited to the Playford mansion by Lady Athelinda
- Edward Catchpool, inspector with Scotland Yard, also invited by Lady Athelinda
- Lady Athelinda Playford, a sprightly and mischievous woman, author of an Enid Blyton-esque series of children's mysteries about a young sleuth, Shrimp Seddon, and her friends
- Viscount Harry Playford, Lady Athelinda's son, a thoroughly self-absorbed, insensitive man, preoccupied with his hobby, taxidermy
- Dorro Playford, Harry's wife, a haughty and self-righteous woman, obsessed with Harry's inheritance from both his mother and his late father
- Claudia Playford, Lady Athelinda's daughter, a callous and caustic young woman, disrespectful of others and frequently cruel, stemming from childhood resentments
- Randall Kimpton, Claudia's fiancée, a doctor and Oxford graduate, originally a Shakespearean scholar, extremely arrogant, and devoted to Claudia, as she is to him
- Joseph Scotcher, Lady Athelinda's secretary, an extremely kind and flattering man, who easily wins people's trust and affection; he is dying of Bright's disease of the kidneys
- Sophie Bourlet, Joseph's nurse, in love with him, as he loves her
- Michael Gathercole, Lady Athelinda's lawyer and literary executor, who read and fell in love with the Shrimp Seddon books while growing up in an orphanage
- Orville Rolfe, Lady Athelinda's lawyer and Gathercole's joint partner in their firm, an extremely fat and gluttonous man
- Hatton, the butler, an elderly and recalcitrant man, always, it seems, afraid of letting slip some secret
- Brigid, the cook, a brusque and put-upon woman, always complaining about her fellow staff and the guests
- Phyllis, the maid, a naive and silly young woman, persecuted by Brigid and enamoured with Joseph
- Inspector Conree, a pompous and bombastic high-ranking Dublin detective
- Sergeant O'Dwyer, Conree's assistant, lacking confidence due to his boss' frequent tongue-lashings
Good Housekeeping wrote about the novel: "Closed Casket is deviously plotted, deeply satisfying and does the grande dame of crime proud."
Sunday Times wrote: "Sparkling second outing for Hannah's re-imagined Poirot. The setting (posh Irish country house), the characters (country lawyers, creepy male secretary, stroppy flapper, etc) and the period vocabulary are all spot on, but it's the utter fiendish unpredictability of the plot that makes Sophie the new Agatha."
Continuity with Christie's original stories
Returning in this novel is Hannah's own creation, Scotland Yard inspector Edward Catchpool, who serves a similar function to Poirot's original sidekick, Arthur Hastings. The story of Closed Casket takes place mere months after The Monogram Murders, in which Catchpool made his debut. This suggests that, like that novel, this one is sandwiched chronologically between The Mystery of the Blue Train (published 1928) and Peril at End House (1932), the latter of which featured Hastings, who before then had not appeared since the novel immediately preceding Blue Train, The Big Four (1927).
Closed Casket features elements popular among Christie and her contemporaries during the golden age of detective fiction, including a blueprint sketch of the house where the murder takes place, an armchair detective's guide featured in Christie and Poirot's debut, The Mysterious Affair at Styles.
The novel takes place in the Irish Free State, an independent state founded in 1922 and lasting until 1937. References to the Free State and Irish nationalism are made in the story, such as the destruction by rebels of homes belonging to descendants of the landed gentry.
Commissioning by Agatha Christie estate
This is the second novel by Hannah to feature Christie's popular hero, Hercule Poirot, a retired Belgian policeman turned private investigator. Its predecessor is 2014's The Monogram Murders, which was the first novel using one of Christie's original characters to be authorised by her estate in the thirty-eight years since her death (excluding novelisations of Christie's plays by Charles Osborne).
A major inspiration for key plot elements and characters seems to have been Dan Mallory, the editor of Sophie Hannah. She was reportedly sceptical of his various claims, hired a private investigator and seems to have integrated many elements from real life into her novel.