Dora Greenfield, “plump and peach-like” (7), meets her future husband Paul as a 20-years-old art student when he teaches a course on medieval woodcarving. He is 33, intelligent, and educated, and he comes from a rich family. He has a violent temper, and Dora feels uneducated and clumsy in his presence. She begins to undermine their marriage by deliberately doing things Paul detests, and after a jealous outburst, she begins to fear Paul and decides to leave him.

Paul accepts this but continues to send Dora “regular weekly letters of reproach” and money (13), which she accepts even as she starts an affair with a frivolous reporter, Noel Spens. She learns that Paul has left London for the country, staying at a lay religious community near an Anglican convent called Imber Abbey and exploring a medieval manuscript.

After a while, Dora tires of Noel and decides to return to Paul, who invites her to the countryside. Hesitantly, Dora agrees, spending the train journey in a carriage with a young boy named Toby and his tutor but not realizing they are heading for the same place. She finds a Red Admiral butterfly on the floor of the carriage and takes it into her hands to save it.