 Young middle-class Englishwoman Joan Webster is determined to have the finer things in life, and to that end she plans to marry Sir Robert Bellinger, a wealthy, middle-aged industrialist whom she does not love. En route to the Island of Killoran (mythical), where her future husband resides, Joan is stranded on the nearby island of Mull. Inclement weather keeps her grounded for a week, during which time she falls in love with young, insouciant naval officer Torquil McNeil. Ignoring the dictates of her heart (not to mention common sense), Joan stubbornly insists upon heading out to sea towards her marriage of convenience, but the exigencies of Mother Nature finally convince her that her future resides on Mull.