A Wrinkle in Time is a young adult science fantasy novel by American author Madeleine L'Engle. The main characters – Meg Murry, Charles Wallace Murry, and Calvin O'Keefe – embark on a journey through space and time, from galaxy to galaxy, as they endeavor to rescue the Murry's' father and fight back The Black Thing that has intruded into several worlds. The novel offers a glimpse into the war between light and darkness and good and evil as the young characters mature into adolescents on their journey.