The Foolish and the Weak
Meg pleads with the three ladies to help them save Charles Wallace. Mrs. Whatsit says that they can do nothing on Camazotz. She also says she will not allow either Mr. Murry or Calvin to return there. Meg realizes that she has to be the one to go back, since Charles understands her, and she is closest to him. Mr. Murry at first refuses permission, and Calvin joins with him. Mrs. Whatsit explains to Meg that if she goes, she will face great danger. Mrs. Whatsit cannot see into the future, so she cannot guarantee a successful outcome. Mr. Murry reluctantly withdraws his objections. Mrs. Whatsit gives Meg her love.

With the help of Mrs. Which, Meg tessers back to Camazotz. Mrs. Which tells her that she has something IT does not. It is her only weapon. But Meg must find out for herself what that weapon is. She goes past the Central Intelligence building to the dome that houses IT. Once inside, she can feel the insidious influence of IT. She approaches IT; Charles crouches beside it. Reading her thoughts, Charles tells her she has nothing that IT does not. She feels hatred towards IT, and starts to get sucked into it. Then she realizes that IT also possesses hate. And in a flash she realizes that what she has that IT does not is love. She looks at Charles, full of love for him. This love frees Charles from the grip of IT, and he and Meg embrace. Suddenly there is a whirl of darkness, and then Meg feels the earth beneath her. She and Charles have landed at home, in the twins' vegetable garden. Calvin and her father are there too. Mrs. Murry emerges from the house with the twins, and there is a joyful family embrace. Mrs. Whatsit, Mrs. Who, and Mrs. Which make a brief appearance, before tessering off to some new location.

Analysis
The last chapter demonstrates what has been implied all along-that love is stronger than hatred, that light is stronger than darkness. Love will conquer if humans remember its power and use it.

Meg's dangerous journey back to Camazotz teaches her more lessons. It is significant that no one else can do this journey, not the ladies, or Meg's father or Calvin. Meg must take the responsibility herself. Significant also is Mrs. Which's refusal to tell Meg what her greatest weapon is. Meg must find this out for herself. She cannot rely on others. This is the exact opposite of the kind of life that prevailed on Camazotz, where there was no individuality and no need for personal responsibility. There was also no danger on Camazotz, since IT took care of every problem. But the message of the novel is that the exercise of individual moral responsibility is the real business of life, and this involves facing and overcoming real dangers.