1830. Neil and Lizzie MacKenzie, a newly married young couple, arrive at the remotest part of the British Isles: St Kilda. He is a minister determined to save the souls of the pagan inhabitants; his pregnant wife speaks no Gaelic and, when her husband is away, has only the waves and the cry of gulls for company. As both find themselves tested to the limit in this harsh new environment, Lizzie soon discovers that marriage is as treacherous a country as the land that surrounds her.