The three ladies enter the hall and the beasts bow in reverence. Meg wants to hug them, but then realizes that they haven’t completely materialized and are only like beams of light. Meg begs them to go get Charles Wallace, but the ladies remind her that that is not their way and there is nothing they can do.
Mr. Murry tries to convince them to let him tesser back to Camazotz to save Charles Wallace, but the ladies refuse to teach him. Calvin then tries to tell them that he should be the one to save Charles Wallace because he almost saved him before, but again the ladies refuse telling him that IT is much stronger in Charles Wallace than it was before. No one speaks, and when Meg asks if the ladies are just going to “throw Charles away” she realizes that they are waiting for her to volunteer to go.
At first Meg refuses and is upset. She tries to hide in Aunt Beast, but the creature will not hold her. Indeed she acts like a child throwing a tantrum . She finally relents and says that she will go, and it is at that moment that the nature of her quest becomes illuminated for her. She can then look at her father and see “love and pride.” Meg understands that it has to be her because she knows Charles Wallace the best.
When Mr. Murry tries to say that he won’t allow her to go, Meg reminds him that her mother would want her to go out into the world, even if faced with prohibitive danger. When Calvin asks her if she has the courage to do this, she answers “no,” but that it doesn’t matter because she is the only one who can go. The ladies know that they may be sending Meg into great danger, but they also know she must be the one to go. They tell her that even the Happy Medium knows she must be the one.
When Calvin tries to understand how the Happy Medium cannot know what is going to happen to Meg, Mrs. Whatsit explains that their lives are like sonnets - poems with strict rules for meter and rhyme but with which the poet has all the freedom to create beauty within the rules. Meg says goodbye to Aunt Beast and to her father. Calvin kisses her and her father hugs her. Meg tells her father that she is sorry for blaming him, but he tells her that he loves her and that what every parent wants is to make things better for their children. He tells her they will be brave for her.
For a parting gift, Mrs. Whatsit gives Meg the gift of love. Mrs. Who gives her a quote: “The foolishness of God is wiser than men; and the weakness of God is stronger than men...” Mrs. Which then tessers Meg off the planet and through the Dark Thing. She again feels cold, but finds herself no worse for wear when she arrives on the hilltop on Camazotz. A voice echoes from around her; it is Mrs. Which telling her that she has the only weapon that can defeat IT, but that she must discover it for herself. Then she is alone.
She walks into the city on Camazotz and is again surrounded by the tall sleek buildings. All the lights are off and it is night. In a strict rhythm, guards come out of the building and walk around, but they do not pay Meg any attention. She tries to rack her brain for what she has that IT does not. Slowly, she makes her way towards the domed building where IT is housed.
She is suddenly rushed into the building as if being sucked in and before her stand IT and Charles Wallace, still under the control of IT. Meg frantically tries to think of what it is that IT doesn’t have, and Charles Wallace answers her thoughts by telling her that there is nothing that IT doesn’t have. Meg can feel the hatred wash over her - hatred for IT and for the shell of a boy that is Charles Wallace. She can feel her mind being sucked into the rhythm of IT. Then IT makes its biggest mistake: it states that Mrs. Whatsit hates her.
Suddenly, Meg realizes that IT is lying to her and that the one thing that IT doesn’t have is love. She begins to think in her mind about how she could love this thing, and she realizes she doesn’t have the strength to love IT. But she does have the strength to love Charles Wallace and so she starts repeating in her mind how much she loves him. This turns into her screaming out her love for the child and Charles Wallace begins to break out of the spell he's under. He runs towards Meg and they embrace.
They are instantly tessered off the planet Camazotz and find themselves rolling around on the ground. It is the twin’s vegetable garden. They find themselves back in their own yard. Mr. Murry and Calvin come running towards them - they all made it back safely. They embrace and soon start towards the house. The twins and Mrs. Murry find them and the entire family joins in a one big embrace, soon joined by the excited Fortinbras.
Charles Wallace tells them to be quiet for a moment and all of a sudden the three ladies are before the entire family. Meg feels so much love for all of them that she says she can almost reach out and touch it. The ladies begin to tell them goodbye and that they have another mission to accomplish, but before they can even say the words the wind sweeps them away.
The closing chapter of the book is a meditation on the largest theme running through the novel: love. Previous chapters have focused on the love shared between families and the way in which love strengthens the characters to meet their respective destinies. There is also a hint of romantic love that gives Meg strength, though other L’Engle novels deal more with this specific kind of love. This chapter focuses on sacrificial love and the qualities of salvation inherent in that kind.
Meg fights the instinct to save Charles Wallace, but as soon as she relents she understands the power of her own gesture. Her gift of sacrificial love is the only thing that can save Charles Wallace. Mr. Murry’s love would not be strong enough, nor would Calvin’s love. It is only because Meg has invested so much of herself in the boy that she is able to save him. L’Engle suggests that it is this kind of love that - sacrificial love for one’s neighbor - that is the true power of salvation in the world. In order to discover true love, however, Meg has to overcome her own feelings of anger, disappointment, and ego.
This kind of sacrificial love also echoes the novel's Christian framework. God’s love - in the biblical narrative - is also a sacrificial love. It is the example of Jesus Christ, mentioned earlier in the book, that Meg’s own act of love alludes to. Christ’s love is the example of the kind of love that can truly defeat the Dark Thing. This is also the same kind of love that Mrs. Whatsit showed in relinquishing her life as a star. Meg will have the opportunity to put aside her anger and discover a more potent force when she's faced with the choice of saving Charles Wallace or suffering his same fate.
The title of the chapter - The Foolish and the Weak - also is an allusion to a passage of the Bible. Once again, in reference to the writings of the apostle Paul, the chapter alludes to the way in which Meg’s own strength and courage are not enough to save her brother. God’s love is stronger than any selfish emotion, and it is this kind of love that Meg must rely on to save her family. In this way, Meg symbolizes the weak and foolish of the world that God uses to defeat evil.
This love contrasts sharply with the emotion of hate, symbolized by IT. Every time that Meg feels hatred, whether for IT or for Calvin or for her father, she is weakened. It is her hatred that allows IT to grab control of her mind. In the end, it is her greatest difference - the ability to love unconditionally against the forces of hate - that allows her to succeed and defeat IT. The closing scene of the book in which the family reunites is a reminder of the strong bonds of love that L’Engle believes can help renew, heal, and elevate humanity.