During their time on Camazotz, the three children first receive instructions and warnings from Mrs. Whatsit, Mrs. Who, and Mrs. Which. Specifically, they tell Meg that her faults will be her greatest strengths. Conversely, Charles Wallace's gift will become his strongest temptation. Calvin must use his communication skills wisely, and the children must remain together.

Left alone, Meg, Calvin, and Charles Wallace begin to observe the eerie uniformity of the planet. All of the children bounce balls and jump rope to the same rhythm. By questioning a delivery boy, Meg and her companions learn more about the society and its regulations. They opt to visit CENTRAL Central Intelligence, the seat of the government, in pursuit of Mr. Murry.

While at CENTRAL Central Intelligence, the children meet a teacher. Alarmed at their questions, the teacher reports the children for "reprocessing." As a result, the children are ushered into an enormous room, where they encounter a creepy man. The man speaks unnaturally, as if he is being spoken through. He is under hypnosis, like everyone else the children have met.

Offering Charles Wallace valuable information, the man hypnotizes Charles as well. Now entranced, Charles leads Calvin and Meg to Mr. Murry. Along the way, Charles Wallace explains that everyone in Camazotz shares the same mind through something called "IT." With the help of Mrs. Whatsit's glasses and Mrs. Who's quotation, Meg and Calvin rescues Mr. Murry from the column he is trapped in. Unfortunately, Mr. Murry has no power to break his son's hypnosis. Instead, Charles Wallace leads the group to IT, a massive, pulsating human brain.

Just as Meg and Calvin begin to succumb to IT's power, Calvin urges Mr. Murry to "tesser." Together, father, daughter, and friend leave behind Camazotz.

Several key things happen to the children on the dark planet Camazotz, where Meg and Charles Wallace have gone to rescue their father, along with their friend Calvin. First, they recognize something is amiss when they see children all bouncing balls in exactly the same way at the same time, as if they are robotic. Later, they see a boy who failed to bounce his ball properly being tortured at the CENTRAL Central Intelligence Building. Another key event is Charles Wallace, because he has too much pride in his intelligence, having his mind taken over by IT. A significant point in the story occurs when the children find the father, Mr. Murry, encased in a glass tube or chamber. Meg is able to get into the chamber by putting on her glasses. Mr. Murry, Meg, and Charles Wallace are able to resist IT's attempts to brainwash and control them long enough to tesseract away from the planet. However, they have to leave Charles Wallace behind. Key events, in summary, are as follows:

• The children note it is creepy and conformist on the planet Camazotz.
• Charles Wallace's mind is taken over by IT.
• The children find Mr. Murry.
• Meg is able to get into the glass tube with Mr. Murry by putting on her glasses.
• Meg, Mr. Murray, and Calvin are able to escape the planet.
• Charles Wallace is left behind.