Isabel Diarmid and her twin sister Margaret are by birth halfway between gentry and common folk. They own a small family cottage on a hill at the head of Loch Diarmid, which they share with their father's second wife and children. Margaret is slowly dying of a wasting disease, and is viewed almost as a saint by the local people.
Isabel's story is told against the backdrop of a religious movement which has swept the countryside: its charismatic prophetess and other leaders speak in tongues and believe they receive the word of God directly. While the local people are swept up in the passion of this movement, Isabel is swept up in her own passion, having fallen in love with a young Englishman whom no one trusts. Before the novel ends Isabel will have experienced love, betrayal, and the impact of a murder.
Biographical and other notes
The fictional "Loch Diarmid" is actually Gareloch; the unnamed "larger loch" is Loch Long; "Lochhead" is Garelochhead; "Loch Goil" is Loch Goil.
After the death of her husband in Italy in 1859, Margaret Oliphant eventually moved to Scotland with her three young children. In the winter of 1861, while working on the biography of Edward Irving, she was put in touch with the handsome, witty Reverend Robert Herbert Story. In early 1862 she visited him and his mother at his manse at Rosneath on the Gareloch - a salt water loch in the West of Scotland. A great friendship resulted from her visit; and more friendships developed or strengthened during a second visit that summer.
Mrs Oliphant's idea for this novel came after hearing about the local religious movement of the 1830s which Reverend Story's father had witnessed and written about.