A Death in Two Parts — Jane Aiken Hodge

When Patience Smith discovers on her 21st birthday that she is penniless, she decides to return to her cousins' home as a companion to her grandmother, the formidable Mrs. Ffeathers, whose main entertainment is manipulating her family. No one complains because Mrs. Ffeathers is very rich and ninety-one years old, and has to die sometime. Surprisingly, the old lady takes a liking to Patience and changes her will, leaving her fortune to the girl. So when Mrs. Ffeathers is found poisoned, it seems that only one person has a financial motive. And in 1950 the sentence of murder is hanging. But fifty years later, the mystery is still unsolved. Long-buried secrets, family betrayals and infidelities are coming out of the closet, and Patience's quiet life is to be blown apart as she is once more the target of a conspiracy … or a killer…