An investigator arrives from Scotland Yard to investigate the murder. He concludes that the letter-writer/murderer is a middle-aged woman among the prominent citizens of Lymstock. Progress in the murder investigation is slow until the vicar's wife calls up an expert of her own: Miss Marple. Jerry conveys many clues to her from his observations and tells her some of his ideas on why Agnes was killed. Elsie Holland, the governess for the Symmington boys, receives a letter. The police observed Aimée Griffith, the doctor's sister, typing the address on the same typewriter used for all the previous letters and arrest her for the letter.