Who is Charles Wallace? Who is Calvin, and Meggie's brothers?

Meg Murry, one of the main characters of the novel, lives in a small town with her mother and three brothers. She is portrayed as an awkward girl who doesn't do particularly well in school nor fit in with the popular crowd. However, this apparent mediocrity conceals her extraordinary math abilities - a subject her father taught her before he disappeared.

Meg's chief struggle in the book involves the challenge to either disown or embrace her particular genius and idiosyncrasies. Ultimately she learns that he personal differences are weapons in her own fight against the Dark Thing and her efforts to save her father.

Charles Wallace Murry is Meg Murry's little brother. Though he is only five years old, he speaks like an adult and has the IQ of a genius. Though he didn't start speaking until he was four years old, a fact that causes others to think he is slow, he began speaking in complete sentences with a vocabulary better than most adults.

Charles Wallace also has the strange gift of being able to read other people's minds and thoughts. His chief struggle in the book is embracing his childhood, though he knows he is infinitely smarter and more talented than the children around him.

Calvin O'Keefe, one of the novel's main characters, travels with Meg and Charles Wallace through space and time to help rescue Meg's father. During the trip, Meg and Calvin grow very fond of each other and begin a courtship. Calvin, as a brother to eleven other siblings, struggles with issues of fitting into his own family. He laments that his family would not even care if he was missing, though he still loves them very much. He is also very different than his family, and exhibits genetic traits not shown in other members of a family. This, he says, makes it even harder for him to fit in. He exhibits a special talent, however, for persuading people towards particular points of view. This is a talent that comes in handy during the children's quest to find Meg and Charles Wallace's father.