Mrs Eldritch

In the short story Strange Jest, Miss Marple mentioned her friend Mrs Eldritch as a parallel of the case she was trying to solve. Mrs Eldritch had a maid who was very hardworking and who polished the linoleum very well. Unfortunately she had polished the bathroom floor so well that when Mrs Eldritch stepped out of her bath, she slipped and fell and broke her leg, with the bathroom being locked. She had to be rescued by the gardener who had to climb in through the window. Miss Marple used Mrs Eldritch as a parallel of a situation where too much activity was self-defeating. In trying to find something (in the case of the story, some hidden treasure), they had first to develop a plan based on knowing the mind of the person who had hidden it, or as Poirot would put it, by using the "little grey cells".