

Poirot has a long discussion with another patient from that day, a retired civil servant from the Home Office, Mr Barnes, who knows that Amberiotis is a spy, and suspects that Blunt was the actual target of the murder: "They're out after Blunt all right. Also present at the surgery was Howard Raikes, a hard-nosed American left-wing activist, violently opposed to Blunt but enamoured of Blunt's niece, Jane Olivera. Her sleazy boyfriend, Frank Carter, had a weak motive, given that Morley had attempted to dissuade her from seeing him. Morley's secretary had been called away by a fake telegram.

Morley's partner, Reilly, seems to have no motive. The movements of people at the dental surgery are inconclusive. Amberiotis dies of an overdose of anaesthetic and it is thought that the dentist has killed himself after realising the accident for which he had been responsible but Poirot does not believe this.

The presence of Blunt, a man thought essential to Britain's economic survival, ensures Japp's involvement in the case. Between Poirot's appointment and Morley's death there were only three patients: Alistair Blunt, a banker Mabelle Sainsbury Seale and a Greek secret agent and blackmailer, surnamed Amberiotis. Later, he hears from Inspector Japp that Morley has died of a gunshot.

He returns to her the shiny buckle that has fallen from her shoe. Hercule Poirot leaves the office of his dentist, Morley, after an appointment, and notices the arrival of Mabelle Sainsbury Seale. Poirot suspects, however, that there is more to the case than at first appears, and soon events confirm his worst suspicions. When Hercule Poirot's own dentist, Henry Morley, is found dead from a gunshot wound, the official verdict is that he has killed himself a verdict apparently supported when it appears that he has given one of his patients a fatal overdose of anaesthetic. It also bears a stark resemblance to one of Christie's previous novels, Three Act Tragedy, which features similar elements with respect to the denouement and also the plot on the whole. It is one of several of Christie's crime fiction novels to feature both the Belgian detective Hercule Poirot, and Chief Inspector Japp. The UK edition retailed at seven shillings and sixpence (7/6) while the United States edition retailed at $2.00. A paperback edition in the US by Dell books in 1953 changed the title again to An Overdose of Death. One, Two, Buckle My Shoe is a work of detective fiction by Agatha Christie first published in the United Kingdom by the Collins Crime Club in November 1940, and in the US by Dodd, Mead and Company in February 1941 under the title of The Patriotic Murders.
