The story begins at the home of Fred and Laura Jesson, where Laura has just entered, looking pale and a little perturbed. The reason for her anxiety is one that no-one would ever expect. Laura has fallen in love. At a café on a railway station, she had met a doctor called Alec Harvey when she got a little grit in her eye. Although they are both already married, they gradually fall in love with each other, continuing to meet every Thursday in the small café, although they know that their love is impossible.