"A Wrinkle in Time" is a science fiction novel by Madeleine L'Engle that follows the journey of a young girl named Meg Murry. She, along with her brother Charles Wallace and their friend Calvin O'Keefe, travels through space and time to rescue her father, who is trapped on a distant planet. The story explores themes of love, courage, and the battle between good and evil. The trio encounters various beings, including the mysterious Mrs. Whatsit, Mrs. Which, and Mrs. Who, who guide them on their quest. They face challenges posed by the dark force known as IT, which represents conformity and oppression. Ultimately, the characters learn the importance of individuality and the power of love.