John Clapperton

In the short story Problem at Sea, Colonel John Clapperton was the husband of Adeline Clapperton. He and his wife were passengers on board a Mediterranean cruise ship together with Hercule Poirot. During the First World War, Clapperton had been wounded and had been admitted to the hospital ran by Adeline. There they had met and soon got married.

General Forbes, a fellow passenger on the ship, was dismissive of Clapperton as a soldier. As he told the other passengers, during the war, Clapperton had been on the music hall stage. During the war, he had been in France "counting tins of plum and apple". He had a minor wound from a stray bomb and then had been sent to hospital and there got lucky. By contrast several passengers took pity on Clapperton because he was constantly bullied by his wife and eagerly sought his company.

Clapperton had a cast iron alibi when his wife was found murdered: he had been ashore and constantly in the company of two young ladies at the time. However Poirot still suspected him because his "self-control was too perfect." "No matter how galling his wife's conduct, it never seemed to touch him". The other fact that Poirot would later use to expose him as the murderer was the fact that during his music hall career, he had been a ventriloquist, and not a conjurer as he pretended to his fellow passengers.

Clapperton had a heart condition and took digitalin. When Poirot exposed his crime, he stood up, collapsed and died from the shock.

Portrayals
John Clapperton was played by John Normington in the film adaptation of the story which was episode 7 of Series 1 of ITV's Agatha Christie's Poirot drama series. the portrayal is faithful to the original story. However, on the adaptation, his heart condition is not mentioned. He did not die. He stood up after the shock of the denouement and tried to run away but was caught and detained.