Thirteen-year-old Meg Murry's classmates and teachers see her as a troublesome student. Her family knows that she is emotionally immature but also see her as capable of great things. The family includes her beautiful scientist mother; her absent scientist father; her athletic 10-year-old twin brothers, Sandy and Dennys; and her five-year-old brother Charles Wallace Murry, a child prodigy genius who can sometimes read Meg's mind.