In The Mysterious Affair at Styles, John Cavendish is one of Emily Inglethorp's stepsons, along with Lawrence. He is the husband of Mary Cavendish.
Characters with a connection to John[]
Mary Cavendish - John's wife
Lawrence Cavendish - John's younger brother
Mr Cavendish - John's father, died before the events of the novel
Mrs Cavendish - John's mother. Never appears in the novel.
Emily Inglethorp - Mr Cavendish's second wife, John's step mother
Cynthia Murdoch - no connection until Curtain, when it is revealed that John is Cynthia's brother in law, as the latter had married Lawrence
Role in the novel and the character's fate (as said in Curtain)[]
He had gone to trial for poisoning Emily because the real murderer had faked his handwriting in a receipt.
Arthur Hastings mentions that John dies before the events of Curtain (presumably in the sixties or seventies), and his widowed wife goes to live in Devonshire.
Portrayals[]
In Agatha Christie's Poirot, John Cavendish was portrayed by David Rintoul.