A Wrinkle in Time is the story of Meg Murry, a high-school-aged girl who is transported on an adventure through time and space with her younger brother Charles Wallace and her friend Calvin O'Keefe to rescue her father, a gifted scientist, from the evil forces that hold him prisoner on another planet. At the beginning of the book, Meg is a homely, awkward, but loving girl, troubled by personal insecurities and her concern for her father, who has been missing for over a year. The plot begins with the arrival of Mrs. Whatsit at the Murry house on a dark and stormy evening. Although she looks like an eccentric tramp, she is actually a celestial creature with the ability to read Meg's thoughts. She startles Meg's mother by reassuring her of the existence of a tesseract--a sort of "wrinkle" in space and time. It is through this wrinkle that Meg and her companions will travel through the fifth dimension in search of Mr. Murry.