Curtain: Poirot's Last Case is a work of detective fiction by British writer Agatha Christie, first published in the UK by the Collins Crime Club in September 1975[1] and in the US by Dodd, Mead and Company later in the same year, selling for $7.95.

[2][3] The novel features Hercule Poirot and Arthur Hastings in their final appearances in Christie's works.

Not only does the novel return the characters to the setting of her first, The Mysterious Affair at Styles, but it reunites Poirot and Hastings, who last appeared together in Dumb Witness in 1937.

Poirot calls on his old friend, the recently widowed Hastings, to join him at Styles Court in solving this case.

Using a wheelchair due to arthritis, and attended by his new valet Curtiss, Poirot will not share the name of the previously unsuspected person, using X instead.

The guests know each other, with this gathering initiated when Sir William Boyd-Carrington invites Dr Franklin and his wife to join him for a summer holiday stay.

Elizabeth Cole tells Hastings that she is a sister of Margaret Litchfield, who confessed to the murder of their abusive father in one of the five cases.

The next morning, Norton is found dead in his locked room with a bullet-hole in the centre of his forehead, the key in his dressing-gown pocket and a pistol nearby.

X was Norton, a man who had perfected the technique of which Iago in Othello (and a character in Ervine's play) is master: applying just such psychological pressure as is needed to provoke someone to commit murder, without his victim realising what is happening.

Poirot intervened with sleeping pills in Hastings' hot chocolate that night, to avert a disastrous rash action.

Anticipating this move, Poirot had drugged both cups, knowing that he had a higher tolerance for a sedative dose that would incapacitate Norton.

In a review titled "The last labour of Hercules", Matthew Coady in The Guardian, on 9 October 1975, wrote that the book was both "a curiosity and a triumph".

He repeated the tale of the book being written some thirty years before and then stated that "through it, Dame Agatha, whose recent work has shown a decline, is seen once more at the peak of her ingenuity."

Coady called Captain Hastings the "densest of Dr Watsons [but]... never has the stupidity of the faithful companion-chronicler been so cunningly exploited as it is here."

Inside the old, absurd conventions of the Country House mystery she reworks the least likely person trick with a freshness rivalling the originality she displayed nearly 50 years ago in The Murder of Roger Ackroyd.

"[5] Maurice Richardson in The Observer of 5 October 1975 summed up: "One of her most highly contrived jobs, artificial as a mechanical birdcage, but an unputdownable swansong.

"[6] Robert Barnard, in A Talent to Deceive, less favourably writes:Written in the 'forties, designed for publication after Christie's death, but in fact issued just before it.

Based on an idea toyed with in Peril at End House (chapter 9) – a clever and interesting one, but needing greater subtlety in the handling than Christie's style or characterisation will allow (the characters here are in any case quite exceptionally pallid).

Murders, Inspector Japp says to Poirot: "Shouldn't wonder if you ended by detecting your own death;" an indication that the idea of Curtain had already formed in the author's mind in 1935.

On 6 August 1975, The New York Times published a front-page obituary of Poirot with a photograph to mark his death.

Dame Agatha explained to Rosalind and Max: “It will cheer you up, when you come back from the funeral, or the Memorial Service, to think that you have got a couple of books, one belonging to each of you!” [12] The final Poirot novel that Christie wrote, Elephants Can Remember, was published in 1972 and takes place in that year, followed by Christie's last novel to be written, Postern of Fate.

Due to its earlier date of composition, Curtain makes no mention of Poirot's later cases in novels published after the Second World War.

Poirot's death was announced in The New York Times with a front-page obituary, a rare honour for a fictional character.

Hugh Fraser again returned to the role of Hastings, for the second time in Season 13 (he also appeared in Episode 2 (“The Big Four”)) after an extended absence from the series; stars such as Alice Orr-Ewing (Judith Hastings), Helen Baxendale (Elizabeth Cole), Anne Reid (Daisy Luttrell), Matthew McNulty (Major Allerton), Shaun Dingwall (Dr Franklin), Anna Madeley (Mrs. Franklin), Aidan McArdle (Stephen Norton) and Philip Glenister (Sir William Boyd-Carrington) were among the other cast.