Meg returns to Camazotz to free Charles Wallace from the clutches of IT. She knows that if she is to succeed, she needs to find a strategy that IT doesn't understand. At first, she feels anger and then hate, but realizes that IT comprehends hate and is using it to pull her into its orbit. But when IT, through Charles Wallace, says that Mrs. Whatsit hates her, Meg knows that is a lie. She also recognizes at that moment that love, which is what Mrs. Whatsit feels for her, is what IT doesn't understand, and she uses love to reclaim Charles. "Charles. Charles, I love you. My baby brother who always takes care of me ... I love you..." she says to him.
This love talk, as well as the emotion behind it, penetrates into a place within Charles that IT can't infiltrate and breaks the spell. Charles suddenly regains a sense of self and rushes into Meg's arms, sobbing and clinging to her. The two are then whirled away from Camazotz and land back home on earth.
It is Meg, Charles Wallace's older sister, who finally frees him from his mental slavery to IT. She does it by exercising the only power that IT does not have--the power of love.
She begins by kything to him:
"Charles, Charles, I love you. My baby brother who always takes care of me. Come back to me Charles Wallace, come away from IT, come back, come home."
Finally, she is able to look at him and cry out loud, "I love you, Charles! I love you!"
Then, after a "whirl of darkness," both Meg and Charles Wallace are transported safely home.
Meg is able to set him free because of her ability to love Charles Wallace.