It's 1965 and Rosie Churchill arrives at run-down Castaway House. But when she uncovers a scandal locked away in the old house she soon realises that secrets never stay buried for long. In 1924 fresh-faced Robert Carver comes to Castaway House to spend the summer with his cousin Alec Bray. But the Brays are a damaged family. As Rosie begins to learn more about Robert the more their stories old and new entwine.