The last word set repeats two words on purpose. Fury is wild, violent anger, and Meg wakes on Ixchel carrying it — at her father, of all people. Resolute means firmly determined, not to be turned aside, which is what she becomes the moment she agrees to go back alone. Futile means certain to fail, pointless; her anger by itself had already proved exactly that against IT. To taunt is to mock someone cruelly in order to provoke them, and IT does it through her brother’s mouth, which is the cruelest arrangement in the book. Fury and futile both appeared earlier, and that repetition is the measurement. The same anger that accomplished nothing in Part 6 is still there in the last chapter. Meg has not been given a new feeling, only a second one to set beside it — and the book ends by making her choose which of the two to use.

The ending can be followed as a climax, a meaningful return, and a final closure rather than as isolated incidents. Meg wakes on Ixchel, healed by Aunt Beast, and her first feeling is not relief but fury — at IT, and at her father, who tessered her away and left Charles Wallace behind. Mrs Whatsit, Mrs Who and Mrs Which arrive, and Mrs Which announces that one of them must go back for the boy. Meg waits for someone else to be named and slowly understands the truth: the three cannot enter Camazotz, her father already tried and failed, Calvin’s words could not reach Charles Wallace, and she alone is close enough to her brother to matter. Terrified, she volunteers. Each of the three gives her something for the road. At the close, “Back to Camazotz, Alone” completes the book’s movement toward resolution.

The closing movement joins resolution, arc, and allusion, allowing the ending to answer the beginning. The chapter is called “The Foolish and the Weak,” and the phrase is not L’Engle’s. Mrs Who, who speaks almost entirely in borrowed lines, hands Meg a sentence from a letter written by Paul of Tarsus to a Greek congregation at Corinth in roughly the middle of the first century — a text now printed in the New Testament as First Corinthians. The argument in that passage is that what looks foolish may be wiser than human cleverness, and what looks weak may be stronger than human strength. L’Engle, who was a practicing Anglican and wrote openly about her faith, uses it here as an allusion: a short reference that asks the reader to carry a second, older text alongside the story. That authorial design makes “Where the Title Comes From” a lesson in deliberate payoff.

Mrs Which tells Meg she owns something IT does not, and refuses to name it. The answer turns out to be the thing scientists have spent sixty years trying to explain. Altruism means helping another at a real cost to yourself, with nothing coming back. For a long time it looked like a flaw in the theory of evolution: if survival rewards looking after yourself, why does a ground squirrel scream a warning that tells the hawk exactly where the screamer is? Two answers arrived. The first is kin selection — helping close relatives protects genes you share with them, so the helping spreads even when the helper dies. The second is reciprocal altruism: in animals that live together long enough to remember one another, helping today is repaid tomorrow, and a reputation for helping is worth having in itself. Neither answer covers what Meg does. She goes back for a brother who cannot thank her, on a planet nobody on Earth will ever hear of, which is why the book gives the last word not to science but to love.

Visual AidThe squirrel that screams a warning