Quick recap
Elinor Carlisle stands trial for poisoning Mary Gerrard, the lodge-keeper's daughter at her rich aunt's house. Mary had won over Elinor's fiancé, Roddy, and even got money from Elinor after the aunt died without a will. The case looks airtight: Elinor made the sandwiches, and Mary died of morphine. Young doctor Peter Lord, in love with Elinor, asks Poirot for help. He interviews everyone and finds clues in a torn label and a rose thorn. The killer is Nurse Hopkins, Mary's aunt, who knew Mary was the rich aunt's illegitimate daughter and stood to inherit everything. Elinor is acquitted and starts to notice Peter Lord.
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