The following day, Poirot is contacted by Maude Williams, who had approached him a few days earlier, telling him that she had known Bentley when they worked together briefly for the same estate agents. She told Poirot that she liked Bentley and did not believe he was guilty or even capable of murdering Mrs McGinty. She now offers to help Poirot who takes up her offer by getting her to pose as a maid in the house of Mrs Wetherby, a resident in the village for whom Mrs McGinty worked as housekeeper, and whose daughter, Deirdre, Poirot suspects may have some connection with the circumstances surrounding Mrs McGinty's murder. During the maid's night off, Mrs Upward's spoiled son Robin, a somewhat flamboyant theatre director, and Ariadne Oliver, a famed mystery novelist who has been working on a theatre adaptation with Robin, leave for an evening at the theatre, leaving Mrs Upward alone at the house. When they return, they find Mrs Upward strangled to death. She has evidently had coffee with her murderer, and the lipstick on a coffee cup and perfume in the air points to a woman having committed the crime. Mrs Upward had invited three people to her house that night: Eve Carpenter, Deirdre Henderson and Shelagh Rendell. Any of the three women could be someone from the photographs. Additionally, the postmistress's assistant, Edna, saw someone with blonde hair enter the house, which points to either Carpenter or Rendell, as Henderson is not blonde. Confusing matters even further is the fact that a book is discovered in the Upward house with Evelyn Hope's signature written on the flyleaf, suggesting Mrs Upward was actually Eva Kane. Poirot connects the final piece of the puzzle when he finds the photo Mrs McGinty saw at Maureen Summerhayes' house. It is of Eva Kane and has the inscription “my mother” on the back. Poirot gathers the suspects together and reveals the murderer – Robin Upward.