The book starts with a description of the Brangwen dynasty, then deals with how Tom Brangwen, one of several brothers, fell in love with a Polish refugee and widow, Lydia. The next part of the book deals with Lydia's daughter by her first husband, Anna, and her destructive, battle-riven relationship with her husband, Will, the son of one of Tom's brothers. The last and most extended part of the book, and also probably the most famous, then deals with Will and Anna's daughter, Ursula, and her struggle to find fulfilment for her passionate, spiritual and sensual nature against the confines of the increasingly materialist and conformist society around her. She experiences a same-sex relationship with a teacher, and a passionate but ultimately doomed love affair with Anton Skrebensky, a British soldier of Polish ancestry. At the end of the book, having failed to find her fulfilment in Skrebensky, she has a vision of a rainbow towering over the Earth, promising a new dawn for humanity: