From a very young age Joan Webster (Wendy Hiller) has shown herself to be a very determined and forward looking young woman - ambitious and driven, she knows what she wants and what she wants is the best. Engaged to a wealthy industrialist, Sir Robert Bellinger, she embarks on the journey that is the culmination of her ambitions, taking the train to Scotland, to the Hebridean isle of Kiloran, where the wedding ceremony is to take place. Arriving in Port Erraig ... she discovers that she can’t make the crossing to Kiloran that night on account of the fog. No matter how single-minded and determined she is to have things her way, there are some things she has no control over.