Agatha Christie killed more fictional people with poison than any other novelist, and did it with unusual accuracy, because she spent the First World War handling the drugs herself.
The Town Hall
Christie was twenty-three and newly married when the war began. She joined the Voluntary Aid Detachment and worked at the hospital set up in the town hall at Torquay, in Devon — first on the wards, then, after influenza kept her off nursing in 1915, in the dispensary that had opened there.
The ward work was real nursing. She recorded more than 3,400 unpaid hours over the course of the war, and she was clear later that the first weeks of it were the worst thing she had ever done: she was squeamish, the wounded came back from France in a state nobody had prepared her for, and she made herself keep going.
The dispensary was a different job and it turned out to be the one that mattered.
Qualifying as a dispenser
Every prescription in 1916 was made up by hand. Christie was trained by the pharmacists she worked with, studied for the Society of Apothecaries examination, and passed it in London on April 13, 1917, qualifying as an apothecary's assistant.
That meant knowing what each drug did, what dose was therapeutic, what dose was fatal, how each one presented in a patient, and how it could be mistaken for something else. She spent the rest of the war dispensing them.
One of the pharmacists she worked under kept a lump of curare in his pocket, and told her he carried it because it made him feel powerful. She used him, more or less directly, decades later.
What it produced
Christie wrote The Mysterious Affair at Styles during the war, in the quiet stretches in the dispensary. Its murder weapon is strychnine, and the plot turns on the fact that a bromide added to a strychnine mixture precipitates the strychnine out, so it settles to the bottom of the bottle and the last dose is the lethal one. It is pharmacologically correct.
She kept it up for fifty-five years. More than half of her eighty-odd novels use poison, and the accuracy is good enough that the Pharmaceutical Journal reviewed Styles favourably in 1920, that toxicologists still use her books as teaching examples, and that at least one real case has been diagnosed from them — in 1977 a nurse in London recognised thallium poisoning in a Qatari child because she had read The Pale Horse, which describes the symptoms in order.
Christie's clinical eye is the thing under her reputation for puzzles. She learned it as a nurse and a dispenser at Torquay, from 1914 to 1918, and she never wrote a poisoning she had not checked.
Related
Sources
- Christie's Devon, on her VAD service and the Torquay dispensary. Accessed September 9, 2026.
- 100 facts about Agatha Christie, including the 1917 apothecary examination. Accessed September 9, 2026.
- How Agatha Christie became an expert on poison. TIME, 2015. Accessed September 9, 2026.
- A is for Arsenic: The Poisons of Agatha Christie, Kathryn Harkup. Bloomsbury Sigma, 2015. Accessed September 9, 2026.
- An Autobiography, Agatha Christie, 1977. Accessed September 9, 2026.