Ruth has been raised in children's homes after losing her mother as a young child. Her mother always told her that she was a Selkie, one of the seal people and eventually her mother would return to the sea. Ruth prefers this version to the official death certificates: suicide by drowning. As an adult, Ruth returns with husband Michael to her mother's native Hebrides. This is a new start for them both in an old manse they're renovating. However during the works they make a gruesome discovery: the buried remains of a special child. This body has been there for over a century, since Rev Alexander Ferguson's time and, as the years roll back to reveal its origins Ruth realises this isn't the only surprise awaiting her.

Scotland, 1860. Reverend Alexander Ferguson, naïve and newly-ordained, takes up his new parish, a poor, isolated patch on the Hebridean island of Harris. His time on the island will irrevocably change the course of his life, but the white house on the edge of the dunes keeps its silence long after Alexander departs.

Based on a real nineteenth-century letter to The Times in which a Scottish clergyman claimed to have seen a mermaid, Secrets of the Sea House is an epic, sweeping tale of loss and love, hope and redemption, and how we heal ourselves with the stories we tell.