Meg
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
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
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.
Mrs. Whatsit
Mrs. Whatsit is one of the three ladies who help Meg, Charles Wallace, and Calvin travel through time to fight the Dark Thing and rescue Meg's father. At the beginning of the book, so steals sheets from a townsperson which causes some to believe her to be a tramp. She, however, is a clumsy and, often silly, lady who befriends Charles Wallace and offers moments of comic relief on their journey.
The reader soon learns that Mrs. Whatsit, in a previous life, was actually a star. She lost her star life doing battle with the Dark Thing; and though she managed to wound the Dark Thing, she herself lost her ability to shine in the sky.
Mrs. Who
Mrs. Who is one of the three ladies that help Meg, Charles Wallace, and Calvin travel through space and time during their quest. She has the idiosyncratic habit of quoting lines from famous literature and philosophy in order to shed light on perplexing moral and ethical dilemmas that the children face on their journey.
Mrs. Which
Mrs. Which is one of the three ladies who help Meg, Charles Wallace, and Calvin travel through time and space in order to fight the Dark Thing and rescue Meg's father. Mrs. Which is the oldest of the three ladies (being many hundreds of millions of years old) and also their leader. She has the particular talent of wrinkling time and space in order to let the children travel great amounts of distance to far planets. She very often does not materialize as an actual person but remains a presence that the children can hear and feel.
Mrs. Murry
Mrs. Murry is Meg and Charles Wallace's mother. She is a scientist and, with Meg's father, comes up with the notion of the tesser, the wrinkle in time. She is greatly troubled by her husband's disappearance, though she has the ability to control her emotions for her children, a talent that Meg greatly envies. Mrs. Murry keeps her hope alive by writing letters every night to her missing husband, though these letters are never delivered.
The Dark Thing
While it is not a character in a physical sense, the Dark Thing personifies evil in the universe. It is described as a black force that blots out the light of stars and planets in the universe. Stars can combat the Dark Thing, but in order to defeat it, they will necessarily lose their own lives.
The Happy Medium
The Happy Medium is an oracle-like character who is able to view different places and different times through her crystal ball. The children meet her in a cave, and though she hesitates at showing them evil and unpleasantness in the universe, she is able to better explain to the children the nature of the Dark Thing and its power.
Mr. Jenkins
Mr. Jenkins is Meg's high school teacher. She is sent to his office after a sarcastic comment in class, and though he tries to understand the situation with her missing father, he ends up being just as uncaring and cold to her as others at the school and in the town.
Sandy
Sandy Murry is Meg's little brother and the twin of Dennys Murry.
Dennys
Dennys Murry is Meg's younger brother and twin brother to Sandy.
IT
IT is the novel's main antagonist. IT is a dismembered brain that resides on the planet Camazotz. IT controls the thoughts and actions of everyone on the planet, stealing the creative energy of the individual.
The Man with the Red Eyes
The Man with the Red Eyes first captures Charles Wallace and is the leader of the CENTRAL Central Intelligence. The man, however, is only a shell through which IT directs ITs energies.
Mr. Murry
Mr. Murry is Meg's father, who had been captured by IT while trying to tesser through the universe. He had been held captive on Camazotz for almost two years before Meg rescues him. He is a scientist who works on experiments for the government.
Aunt Beast
Aunt Beast is a tentacled creature that heals Meg after a dangerous tesser to the planet Ixchel. Aunt Beast has no eyes, but has other deep senses. Aunt Beast possesses an inner goodness that heals Meg and teaches her about love.
