Dumb Witness

In the small English town of Market Basing, Emily Arundell, a wealthy, sharp-witted woman in her seventies and the last surviving member of a distinguished family, dies on May 1st after a short illness. Her death is unremarkable, but her will causes a scandal: Made only ten days before she died, it leaves the bulk of her considerable fortune to Wilhelmina Lawson, her timid companion, bypassing her three surviving relatives entirely.

The narrative shifts back to the Friday before Easter, when Emily prepares to host her family at Littlegreen House. Her nephew Charles Arundell is charming but untrustworthy, having once forged a check on Emily's account. His sister, Theresa Arundell, is a stylish, nearly bankrupt socialite engaged to Dr. Rex Donaldson, an ambitious but penniless local physician. Their cousin Bella Tanios is a dutiful woman married to Dr. Jacob Tanios, a Greek doctor, a union Emily's old-fashioned family considers beneath them. Emily is autocratic and shrewd, harboring no illusions about her relatives' flaws. Her wirehaired terrier, Bob, has a habit of dropping his rubber ball down the stairs.

Over the Easter weekend, each relative privately angles for money. Charles asks Emily directly for a hundred pounds and is refused; he warns her, half-jokingly, that hoarding her wealth is a good way to get "bumped off." Tanios pressures a reluctant Bella to approach Emily about their children's education. On Tuesday evening, Charles nearly trips over Bob's ball at the top of the stairs, and Emily tells Miss Lawson to put it away.

That night, Emily rises and falls headlong down the staircase. Charles finds Bob's ball at the top and declares it the cause. Later, however, Emily hears Bob barking to be let in at five in the morning, meaning he was out all night and could not have left the ball on the stairs. She also recalls putting the ball away herself. With grim certainty, she concludes someone deliberately caused her fall.

Emily writes a guarded letter to the Belgian detective Hercule Poirot, requesting help with a "strictly private" matter involving "the incident of the dog's ball." She also instructs her solicitor to draw up a new will leaving everything to Miss Lawson, the one person who could not have benefited from the accident. The letter is accidentally mislaid and never sent.

Over two months later, the letter reaches Poirot. The maid Ellen discovered it in a blotter after Emily's death and posted it belatedly. Poirot's friend and narrator, Captain Arthur Hastings, dismisses the letter, but Poirot finds the date discrepancy significant and drives with Hastings to Market Basing.

They find Littlegreen House for sale, now owned by Miss Lawson. Posing as a prospective buyer, Poirot tours the house with Ellen as guide. When Hastings stumbles over Bob's ball at the top of the stairs, Ellen mentions Emily's similar fall. While Hastings distracts Ellen, Poirot discovers a nail driven into the skirting board, freshly varnished to conceal it: evidence that a thread was stretched across the staircase to trip Emily. Ellen also mentions that in her final delirium, Emily spoke of "Bob's ball" and "a picture that was ajar." Poirot connects these words to a china jar in the drawing room depicting a dog locked out all night. Emily was trying to say that Bob, like the dog on the jar, was out all night and could not have left the ball on the stairs.

Poirot reveals his identity to the servants and conducts a series of interviews. Dr. Grainger, Emily's physician, says her death was unsurprising given her liver condition. Miss Caroline Peabody, a shrewd elderly neighbor, calls the will suspicious. Julia and Isabel Tripp, eccentric spiritualist friends of Miss Lawson, describe a séance the night Emily fell ill during which they saw a luminous haze around Emily's head.

In London, Poirot interviews the suspects. Theresa asks him to help break the will. Charles reveals that Emily showed him the new will during the last weekend before her death, telling him the family was disinherited; Theresa is shocked, insisting Charles never told her this. Miss Lawson reveals that Charles stole money from a drawer and threatened to "bump off" Emily over Easter. Bella, nervous at the Durham Hotel, blurts out "About my husband?" when Poirot mentions Emily's letter and reveals that Emily poured away a medicine Tanios prepared. Tanios himself blames the influence of spiritualism on the will. Poirot also learns Tanios made an unexplained solo visit to Emily the Sunday before she died. When Bella follows Poirot into the hall to say she has something to tell him, her husband's appearance makes her fall silent.

Further investigation yields critical evidence. The local chemist reveals Bella purchased a double quantity of chloral hydrate, a powerful sleeping drug. Dr. Grainger rules out arsenic poisoning, insisting Emily died of yellow atrophy of the liver, a severe degenerative condition consistent with her medical history. Miss Lawson then provides a seeming breakthrough: she saw a figure kneeling on the stairs the night of Easter Monday, identified by a brooch bearing the initials "T.A." reflected in her bedroom mirror. Poirot realizes the critical flaw: Initials seen in a mirror are reversed. If Miss Lawson read "T.A.," the actual initials were "A.T.," for Arabella, the full form of Bella's name. Bella, not Theresa, was on the stairs that night.

Bella flees her husband with the children and takes refuge with Miss Lawson. Tanios visits Poirot, claiming his wife is mentally unwell and asking to be informed if she contacts him. Poirot helps Bella hide at the Coniston Hotel near Euston and gives her a sealed document containing his reconstruction of the case, hoping to persuade her to reveal what she knows. She phones promising proof the next morning, but the following day she is found dead from an overdose of chloral hydrate. All her papers, including Poirot's document, have been burned.

Poirot assembles the suspects at Littlegreen House and delivers his full reconstruction. The luminous halo seen during the séance was not a spiritual manifestation but phosphorescent breath, the signature symptom of phosphorus poisoning. A tiny dose of phosphorus concealed inside one of the liver capsules Emily took after meals produced symptoms identical to her long-standing liver disease.

Poirot identifies Bella as the murderer. Unhappy in her marriage and desperate for independence, she saw Emily's money as her only path to a new life and a proper English education for her children. She had chemistry knowledge from assisting her professor father in his laboratory. She first tried the crude method of the thread across the stairs, and when that failed, she employed phosphorus poisoning via the liver capsules. After reading Poirot's reconstruction, she burned it and took the fatal overdose.

Miss Lawson, weeping, confesses that when the dying Emily asked for the will, she told Emily it was at the lawyer's office, preventing Emily from destroying it. In the aftermath, Theresa marries Donaldson, who becomes a successful specialist. A settlement divides the estate among Miss Lawson, the Arundells, and the Tanios children. Bob the terrier, the "dumb witness" whose habits provided the key to the case, becomes Hastings's devoted companion.