Shades of Murder — Ann Granger

In 1889 the late Cora Oakley's husband William was put on trial for her murder. The case was dismissed, but Oakley fled the country, never to be heard of again.

Over a hundred years later, the only remaining members of the Oakley family are two elderly sisters who, after years of struggling to maintain their dilapidated ancestral home, have decided to sell up. But then Jan, a young Polish man who says he is William Oakley's great-grandson, comes to visit, and claims half the profits from the sale of the house. When Jan is found dead, poisoned by the same substance used to kill his great-grandmother, it seems that the shadow of murder has returned to haunt the Oakley family once again, and Superintendent Markby must look back at the events of a century ago to find the killer...