Although Poirot was reluctant to investigate what, on the face of it, would appear to be a domestic matter, the feisty Mrs Todd prevailed upon him and he agreed to take up the case. Poirot's investigations revealed that Eliza had been tricked and enticed away by the prospect of a house she had inherited in Carlisle because her tin trunk was wanted for a crime. It was, according to Poirot, "a trunk of pedigree, a trunk of assured respectability."
Mrs Todd described Eliza Dunn as middle-aged, stout, black hair turning grey. She was "most respectable". She had been ten years in her last place before joining the Todd household.
In the ITV 1989 adaptation of the story, Eliza Dunn is portrayed by Frieda Dowie. Here she had been tricked with a cottage in Keswick rather than in Carlisle but otherwise the portrayal is very faithful to the original.
In NHK's anime adaptation The Adventure of the Clapham Cook, Eliza Dunn is considerably younger. She is described as a young woman of thirty two and she had worked ten years as a cook at the last place of employment and three years at the Todds. She had a grandmother named Jane Emmott (she was the only living descendant). Her grandmother had a friend named Ms Leech. It was she who supposedly have a lot of money which she left to Jane Emmott's descendents. In this adaptation, Eliza Dunn rejoins the Todd household at the end of the show. The Todds welcome her back, acknowledging that it was not her fault. Mr Todd even gives her a raise. The character of Eliza Dunn in this adaptation is voiced by Chieko Matsuhara.