Closed Casket is a work of detective fiction by British writer Sophie Hannah, featuring Agatha Christie's Hercule Poirot.

She has disinherited her son Harry and daughter Claudia in favor of her charismatic secretary, Joseph Scotcher, who is terminally ill and has only weeks to live.

At the dinner where Lady Playford announced the change to her will, Kimpton recognized that there would now be multiple potential suspects, and slipped strychnine into Scotcher’s drink.

Good Housekeeping wrote about the novel: "Closed Casket is deviously plotted, deeply satisfying and does the grande dame of crime proud."

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.

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.

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.

This is the second novel by Hannah to feature Christie's popular hero, Hercule Poirot, a retired Belgian policeman turned private investigator.