The novel opens with World War I raging all over Europe. A young American student, studying architecture in Italy, offers his services to the Italian army. In Gorizia, he is wounded in the knee and is sent to recuperate in a hospital in Milan. He falls in love with an English nurse, Catherine Barkley, lives with her, and she becomes pregnant. He returns to the front in Gorizia and is caught in the Italian retreat. In order to save his life, he deserts his post and goes away to a hospital in Milan to take Catherine and go some place where they can start life anew. They go to Switzerland but cannot live happily, for a fresh tragedy awaits them. Their eagerly awaited son is stillborn and Catherine who can never have a normal delivery, dies after a Caesarian operation.