 "A Wrinkle in Time", "A Wind in the Door" and "A Swiftly Tilting Planet" are primarily about Polly's mother, Meg Murry (later Meg Murry O'Keefe) in her teen years and young adulthood, and about Meg's brother Charles Wallace Murry.The other volume in the Time Quintet, "Many Waters", is about Polly's other uncles on her mother's side, Sandy and Dennys Murry.Together with the four books in which Polly appears, they are known as the Murry-O'Keefe books.