A Wrinkle in Time by Madeleine L’Engle
Meg Murry, her younger brother Charles Wallace, and Calvin O’Keefe find themselves drawn together. Meg is in high school and feels ugly and awkward. Charles Wallace is about five years old and extremely intelligent. He speaks like an adult and has a mind that understand his parents’ work in physics. Yet he still has the emotions and thoughts of a child his age. Calvin is a couple years ahead of Meg in school, extremely popular at school, out of place in his own family.
This unlikely trio meet another trio that is even more unlikely. Meg and Charles Wallace’s father has been missing for a few years. Mrs. Whatsit, Mrs. Who, and Mrs. Which, three extremely odd ladies, move into the haunted house in the neighborhood. They guide the children the direction needed to find. Mr. Murry. They learn about his studies and learn how to tesseract.
This is an excellent story written for older children. It does not lose anything when read, or re-read the older the reader. The theory for tesseract is sound science. People who travel in space undergo and time shift. This book tries to help explain how there is a wrinkle in time space continuum.