One, Two, Buckle My Shoe

The novel is a Hercule Poirot mystery centered on a dentist's suspicious death and the tangled secrets of his patients.

On a busy London morning, several people converge on 58 Queen Charlotte Street, the dental practice of Mr. Henry Morley. Morley is irritable because his assistant, Gladys Nevill, has been called away by telegram to tend a sick aunt. He suspects the telegram is a ruse arranged by Gladys's fiancé, Frank Carter, an unemployed insurance clerk Morley considers unsuitable. Other morning patients include Mr. Amberiotis, a Greek man; Miss Mabelle Sainsbury Seale, a middle-aged woman from India; and Alistair Blunt, head of England's most powerful banking firm and a figure widely considered essential to the country's financial stability.

Hercule Poirot arrives for a routine checkup. During treatment, Morley mentions his next patient is Blunt and remarks that he recently recognized a patient's face but cannot place it. As Poirot leaves, he helps Sainsbury Seale retrieve a shoe buckle wrenched off against a taxi door and notes her brand-new patent leather shoes with ornate buckles.

That afternoon, Chief Inspector Japp of Scotland Yard telephones: Morley has been found shot dead, an apparent suicide. At the scene, only Morley's fingerprints are on the pistol, but the body's position seems wrong and there are faint drag marks on the carpet. The buzzer last sounded at 12:05 for Amberiotis, who claims he left at 12:25 and found Morley normal; the 12:30 patient was never summoned. Alfred Biggs, the page boy, found the body around 1:30. There is no known motive, no note, and the pistol was not known to be Morley's.

Interviews reveal key details. Morley's sister Georgina insists he would never have killed himself. Gladys returns to discover her aunt is perfectly well; the telegram was a hoax. Alfred reveals that Howard Raikes, a young American who had an appointment with Mr. Reilly, and Frank Carter both entered the house that morning and left without being seen. Mr. Reilly, Morley's Irish partner, says Morley was the last man to commit suicide. Blunt confirms Morley seemed normal during his appointment. Outside the Gothic House, Blunt's Chelsea Embankment home, his niece by marriage Jane Olivera blurts, "Oh, but that's absurd!" upon hearing of Morley's death. At the Savoy, Japp and Poirot learn that Amberiotis died just half an hour earlier.

Medical findings show Amberiotis died from an overdose of adrenaline and novocaine, the local anesthetic used by dentists. Japp considers the case closed, reasoning Morley made a fatal error and shot himself. Poirot objects, noting that dentists give standardized doses automatically. He privately lists unresolved questions involving information that Amberiotis had connections to espionage, Carter's motive, Raikes's behavior, and Mr. Barnes, a retired Home Office official who was among the morning's patients. Poirot visits Barnes, who argues that powerful forces want to eliminate Blunt and that Morley was approached to kill Blunt in the dentist's chair, refused, and was murdered. The drag marks support this theory: If Morley was shot in his adjacent office rather than the surgery, the body had to be moved.

Sainsbury Seale walks out of her hotel one evening and never returns. Poirot notes her evening shoes are a size smaller than her day shoes. Raikes, when interviewed, cannot account for his movements during the critical period. Gladys visits Poirot, arguing that a dentist could not accidentally overdose a patient because dosages are completely standardized; she fears the alternative implication that Morley killed Amberiotis deliberately. Jane Olivera reveals that three months earlier, Sainsbury Seale accosted Blunt, claiming to be "a great friend of your wife's." Privately, Jane confesses she arranged Raikes's dental appointment so he could meet Blunt, which explains her alarmed reaction on the doorstep.

Over a month later, police enter the flat of Mrs. Albert Chapman at King Leopold Mansions in Battersea. In a fur chest they find a decomposed body with its face battered beyond recognition, dressed in Sainsbury Seale's clothes, her handbag stuffed alongside. Poirot notices the shoes are shabby and worn, though Sainsbury Seale's buckled shoes were brand new. In Chapman's address book, Morley is listed as her dentist. Poirot insists on dental identification: Morley's successor examines the teeth against professional charts and identifies the body as Mrs. Chapman, not Sainsbury Seale. Sainsbury Seale's belongings were on Chapman's body, but Sainsbury Seale herself has vanished.

The Foreign Office shuts down the investigation, citing Albert Chapman's intelligence work abroad. Blunt invites Poirot to his country house, Exsham, and privately hires him to find Sainsbury Seale. He discusses his will, which provides for Mrs. Olivera (Jane's mother), Jane, and his second cousin Helen Montressor, a poor relation on the estate. Poirot discovers Carter working as a gardener under a false name; Carter claims a mysterious woman recruited him for secret government work. A shot is fired at Blunt in the garden. Raikes tackles Carter, who is found holding a pistol and insists the gun fell at his feet. Carter is arrested; the pistol is a twin to the one that killed Morley.

Poirot visits Carter in custody and extracts the truth: Carter entered Morley's room at about 12:26 to confront him but found Morley already dead, hand stone cold, blood dried around the wound. Poirot believes him. This means Morley was killed well before noon, and the man who treated Amberiotis was the murderer impersonating the dentist.

During a church service at Exsham, Poirot has his breakthrough. He realizes the case has been a "forced card," designed to make him see a political crime targeting Blunt, when it is actually a private crime committed by Blunt himself. Every piece of misdirection was intended to keep Poirot looking in the wrong direction. Poirot obtains a marriage certificate recording the union of Martin Alistair Blunt and Gerda Grant. Helen Montressor is arrested.

In a climactic confrontation at the Gothic House, Poirot reveals the complete solution. Before marrying the wealthy Rebecca Arnholt, Blunt was already secretly married to Gerda Grant, an actress. Gerda acquiesced to the bigamy and lived under aliases, including Mrs. Albert Chapman and later Helen Montressor, the real Montressor having died in Canada years earlier. The danger arose when Sainsbury Seale, who had known Gerda in repertory theatre, recognized Blunt and innocently mentioned the connection to Amberiotis, a blackmailer who began extorting Blunt. Blunt killed Morley after his own appointment, then posed as the dentist and injected Amberiotis with a lethal overdose. He staged Morley's death as suicide, dragging the body from the office to the surgery. Gerda had already murdered Sainsbury Seale at King Leopold Mansions, then impersonated her at the hotel before vanishing. The dental charts were switched so the body would be identified as Mrs. Chapman, directing police to search for the wrong woman. Carter was recruited as a gardener under a false pretext, with a pistol planted to frame him.

Blunt admits everything, arguing his national importance justifies the murders. Poirot acknowledges Blunt's value but insists every life has equal worth: "I am not concerned with nations, Monsieur. I am concerned with the lives of private individuals who have the right not to have their lives taken from them." Officers arrest Blunt. Poirot tells the waiting Jane and Howard to build their new world with freedom and pity. Walking home, Poirot is joined by Barnes, who reveals a final surprise: Barnes himself is the real Albert Chapman, agent Q.X.912, meaning there never was a Mrs. Chapman in intelligence and the entire cover story was Blunt's fabrication.