Madeleine L'Engle was an American writer of fiction, non-fiction, poetry, and young adult fiction, including A Wrinkle in Time and its sequels: A Wind in the Door, A Swiftly Tilting Planet, Many Waters, and An Acceptable Time. Her works reflect both her Christian faith and her strong interest in modern science.

Young adult literature (YA) is typically written for readers aged 12 to 18, and includes most of the themes found in adult fiction, such friendship, substance abuse, alcoholism, and sexuality. Stories that focus on the challenges of youth may be further categorized as social or coming-of-age novels.