Meg, Charles, and Calvin enter the building. Inside, they ask a man how to see whoever's in charge, and when he finds out they don't have the right papers, he regretfully tells them that he'll have to report them for reprocessing (which, from his words, sounds like a painful experience). He mutters something about how he doesn't want to get in trouble and have to see IT. He feeds some papers into a wall, and the wall suddenly disappears to give way to a huge machine room. The children begin walking through that, and find themselves after a long while in front of a man with red eyes in a chair on a platform.
Camazotz, in all its efficiency, treats people not as unique individuals but as machine parts which must be made all the same. Its use of words like "reprocessing" in terms of handling people again hints at the novel's discomfort with anything—technology or political philosophy, that treats humans as anything other than humans.
As soon as they are near him, Charles begins to feel something trying to take over his mind, but he is able to resist. The man with red eyes is able to communicate with them without opening his mouth: the children simply hear a kind and gentle voice in their brains, though Meg senses with fear the presence of the Black Thing in him. The man's eyes have a strange red glow, and there's a light above his head that glows and pulses in a hypnotizing rhythm.
Yet another form of communication is introduced to the children on this new planet: a way to talk directly to people's minds. The seeming gentleness of the man's voice in their minds is another kind of deception, and shows that evil does not have to be violent. The glow of the man's eyes and the light pulsing behind him to the general hypnotizing rhythm suggests that the man is himself a kind of avatar, a body that is controlled by another.
The man with red eyes seems to have been expecting Meg and Charles, but not Calvin (who is apparently an unpleasant surprise). Still, he doesn't seem too bothered, and is set on convincing them that they must submit to him. Charles closes his eyes and warns Meg and Calvin that if they look into the man's eyes, he'll hypnotize them. The man is amused and pleasantly tells them that everything will be a lot easier if they don't try to fight him. They will be happy, he goes on, like everyone else on the planet, and will never have to make any decisions for themselves again if they just give in. Charles, at whom most of the man's speech seems to be directed, sharply rejects everything he says. But the man begins reciting the multiplication table in a way that seems to be invading the children's skulls, and to stop it from getting to them, Charles shouts nursery rhymes, Calvin yells the Gettysburg Address, and finally Meg screams, "Father!" It is this that jolts her out the darkness her mind had been falling into. Laughing, the man stops reciting the multiplication tables and tells them that they passed the preliminary test, which apparently was preventing him gaining control of their minds that way.
The man with red eyes offers total conformity to the children, and Meg sees for the first time what that means: not thinking for yourself and not making decisions for yourself, which is clearly a horrific reality on Camazotz. The children must reach back to the culture and traditions of a free country, America, to fight against the conformity the man with red eyes tries to push on them. The freedom of expression in nursery rhymes and in Lincoln's Gettysburg address is an antidote to the poison of the man's language of sameness, as is Meg's invocation of her love for her father.
The man with red eyes seems to be most focused on Charles Wallace, and he invites Charles to mentally probe him to find out who he is. Charles looks into the man's pulsing eyes, and after a while, slowly begins walking towards him. At the last minute, Meg screams as she sees the irises of her brother's eyes disappearing and tackles Charles to the ground, breaking the trance he was in. The man with red eyes is not pleased.
Charles seems to think he can stand up to the man with red eyes, but the outcome of their interaction shows this isn't true. Charles is overconfident, not heeding the quote from Goethe given to him by Mrs. Who in Chapter 6. Meg's love for her brother causes her to save him from the dangerous hypnotism of the man with the red eyes, even though she had to physically tackle him in the process.
To prove that Charles must be permitted to complete this in order to advance to the next level, the man with red eyes has a synthetic turkey dinner brought out, which tastes delicious to Meg and Calvin but like sand to Charles, because he's blocking the man entirely from accessing his mind. The man can just get through the chinks in Meg's and Calvin's minds to change their idea of taste.
What looks and tastes like a real turkey dinner is actually totally fake, just as the people of Camazotz have the semblance of happiness in uniformity but in fact are just acting out a kind of fake, enforced happiness.
Finally, at the man's insistence that there's no other way for the children to advance to the "next level" except for Charles to mentally probe him, Charles agrees to try to go into the man's mind again, which Meg is not happy about. This time, the irises of Charles' eyes entirely disappear, and his eyes begin to twirl and glow like the man's. Turning to Meg, he speaks to her, but Meg and Calvin instantly realize from his weird smile and the way he talks that this is not Charles.
Charles is overconfident in his mental abilities and plunges into IT, foolishly and proudly thinking that he is strong enough to take IT on, understand IT, and emerge unscathed. Based on the Goethe quote from Mrs. Who Charles ought to have recognized that there are limits even to what he can know and understand, that what and how much you know is not enough to fight back against and overcome conformity.