"The Greengage Summer" is a novel by Rumer Godden that tells the story of a family vacationing in France during the summer of 1945. The narrative follows the experiences of a young girl named Jill, who becomes enchanted by the beauty of the countryside and the complexities of adult relationships. As Jill navigates her feelings and observations, she encounters various characters, including a mysterious French man and her own family members, who each contribute to her understanding of love, loss, and growing up. The novel explores themes of innocence and the transition into adulthood against a backdrop of post-war change.