Agatha Christie Wiki

The Lernean Hydra is a short story by Agatha Christie which was first published in the U.S. in This Week in September 1939. It was first published in the U.K. in The Strand Magazine in December 1939. In 1947, the story was grouped with 11 others, a foreword was added, and published as The Labours of Hercules.

The setting is on the eve of one of Poirot's many planned retirements. He wants his crowning achievement to be a series of 12 cases which he will specially selected to match those of the Twelve Labours of Heracles in Greek mythology. In the sequence of the labours pursued by Poirot, The Lernean Hydra is the second of twelve. It was preceded by The Nemean Lion and followed by The Arcadian Deer.


Poirot is asked to help a country doctor whose life is being destroyed by malicious rumours that he poisoned his wife. To Poirot, rumours grow like the heads of the hydra.

Plot summary

(may contain spoilers - click on expand to read)

Poirot is asked for help by a physician, Dr Charles Oldfield, who has a practice in Market Loughborough, a small village in Berkshire. His wife died just over a year ago and the malicious talk in the village is that he poisoned her. People are avoiding him and several poison pen letters have been sent to him but he can do nothing to stem this tide of ill-intentioned gossip – like the heads of the Hydra, when one source of the gossip is cut off, another grows in its place. So, his ultimate aim was to cut the main source of the gossip, just like the hydra had been slayed by cutting its vulnerable head. Mrs Oldfield was a difficult invalid whose death was put down to a gastric ulcer, whose symptoms are similar to that of arsenic poisoning. She left her husband a not-considerable sum of money and, under pressure, Oldfield admits that a lot of the talk revolves around Jean Moncrieffe, his young dispenser, who he wants to marry but dare not because of the talk. Poirot travels to Market Loughborough and meets Jean. She is frank about her relationship with Oldfield and her dislike of his wife but opposes Poirot's idea of an exhumation and autopsy on the body. Poirot makes the rounds of the village, insinuating that he is connected with the Home Office and thereby generating much hypocritical murmurs of sympathy for the doctor and, more importantly, names of who said what and when. From this he learns of the present whereabouts of two servants of the Oldfields who left their employ after Mrs Oldfield died; Nurse Harrison, who tended to the patient, and Beatrice, the family maid. Nurse Harrison tells a story of overhearing Jean and the Doctor talking about the imminent death of his wife in which it was clear that this was an event that both of them were impatiently waiting for. The nurse is certain that Beatrice must have overheard the talk as well. Poirot tells her of the supposed plans of exhumation and the nurse considers this news and then tells him she agrees that such a thing should be done. While being interviewed, Beatrice slyly denies overhearing any conversation but tells him of several suspicious stories of Jean making medicines or pots of tea for Mrs Oldfield which the nurse poured away or changed before the patient could take them.

Poirot does indeed get permission for an exhumation and the body is proved to be riddled with arsenic. Nurse Harrison is shocked and tells Poirot a new story of seeing Jean filling up a make-up compact with a powder from the dispensary. Poirot alerts the police who find such a compact in the bureau of the bedroom of Jean's lodgings. They show it to Nurse Harrison who excitedly confirms that is the one she saw…only for Poirot to tell her that such compacts have only been manufactured for three months and that he had his valet, George, follow her some days previously, witnessing her purchase of a compact at Woolworths and then travelling to Jean's lodgings to secrete it there. Trapped and broken, Nurse Harrison admits the murder.

Poirot speaks with Jean and tells her that the conversation Nurse Harrison claimed to have overheard seemed psychologically unlikely as two possible conspirators would never had had such a conversation in a place where they could be easily listened to. He observed the nurse's positive reaction when he told her of a possible exhumation and then had her followed by Georges who witnessed the buying of the compact and the laying of the trap for Jean. The motive was jealousy as Nurse Harrison was convinced by Oldfield's kind manner over several years that he intended her to be his bride.


Research notes

Film, TV, or theatrical versions

Agatha Christie's Poirot

A television film with David Suchet as Poirot was produced as episode 4 of Series 13 of the ITV series Agatha Christie's Poirot, first broadcast on 6 November 2013. The themes from several stories in the collection were woven loosely together for the plot of the film but nothing from the Lernean Lion was used for the adaptation.

Publication history

  • 1939: This Week, (New York), 3 September 1939 (as "Invisible Enemy")
  • 1939: The Strand Magazine, Issue 588 (London), December 1939 - with illustrations by Ernest Ratcliff
  • 1947: The Labors of Hercules, Dodd Mead and Company (New York), 1947, Hardback, 265 pp
  • 1946: Ellery Queen's Mystery Magazine, vol. 7 no. 27, Feb 1946, as "The Hydra of Lernea, or The Case of the Gossipers".[1]
  • 1946: Ellery Queen's Mystery Magazine "Overseas Edition for the Armed Forces", vol. 7 no. 27, Feb 1946, as "The Hydra of Lernea, or The Case of the Gossipers".
  • 1947: The Labours of Hercules, Collins Crime Club (London), September 1947, Hardback, 256 pp
  • 1956: The Creasey Mystery Magazine, vol. 1 no. 2, Sep 1956.[2]