death of Miss Barrowby. Poirot sends a letter to Rosebank to provoke a response from the next of kin, and he duly receives a reply from Mary Delafontaine, the dead woman's niece, saying that his services are no longer required. Nevertheless, he goes to the house and admires the well-maintained garden with its spring flowers and edging of shells. Let into the house by a maid, the first person he meets is a young Russian girl called Katrina Reiger, who speaks cryptically of the money that by rights is hers. She is interrupted by Mrs Delafontaine and her husband who dismiss Katrina and meet Poirot. They seem shocked to find that he is a detective. Poirot interviews the local police inspector who tells him that they now know that Miss Barrowby died from a dose of strychnine but the problem is that the victim and her two family members all ate the same meal. The Delafontaines are suspected as they will inherit a large sum of money, which they very much need, but it was Katrina who gave her employer her medicinal powders and it is possible the strychnine was in those. However, Katrina does not appear to benefit from Miss Barrowby's death, and would, in fact, have been out of a job. The next day, brings the news that most of the estate has been left to Katrina, thereby providing a motive, and she is detained by the police. A packet of strychnine powders is found under Katrina's mattress which seems to clinch the matter. Poirot though is not convinced and arranges matters in a methodical order in his own mind. It is then he remembers the garden. He sends out Miss Lemon to make particular enquiries and then interviews Katrina who confirms that she ate separately from the family, as she always did, but had the same food as them. Poirot, after consulting with Miss Lemon, calls at Rosebank and sees Mrs Delafontaine. At the front door, he points to the unfinished row of shells – the only unsymmetrical item in that well-maintained and symmetrical garden – and points out they are oyster shells. Miss Lemon found the fishmonger who sold the oysters to the Delafontaines. They fed Miss Barrowby poisoned oysters and planted the shells in the garden to hide from Katrina and the maid. Mrs Delafontaine confesses that she and her husband had been pilfering money