The criterion log
An arc can be read only by setting a character’s decisions side by side, so the chapter’s first tool is a table of them. The criterion log lists, for one character, the five to eight largest decisions in the book, in order, with four entries for each: where it falls, as a percentage of the book; what the options were; what the character chose; and the rule by which they chose, written as a short imperative (find out for yourself, protect the family). Reading down the last column shows the arc. If every entry is the same rule, the character has none, which may be the book’s design or its fault. If the rule changes once, the change is the hinge, and the decision on either side of it should be tested for the conditions below. If it changes several times, the arc is staged, and the gaps between changes should be long enough for each new rule to be tried.
The log has a second use, which is to find decisions the draft has not written. A writer who cannot fill the rule column for a decision has usually written an event rather than a choice: the character did something without the book showing the alternative or its cost. Where the log shows a gap of a quarter of the book or more with no decision in it, the character has stopped choosing, and the arc is being carried, if at all, by circumstance.
The four conditions of a change
A change convinces when four conditions are met, and together they meet Forster’s test of a round character, that a change should surprise and yet convince.
The first condition is the seed. The new criterion must be present in the book before the hinge, so that the reader, looking back, finds the change prepared. The usual seed is another character who already holds the rule, so that the protagonist adopts something the book has shown working for someone else. A rule another character refuses to follow can also serve as a seed. A second form is a moment when the protagonist glimpses the new rule and sets it aside. The seed should be placed far enough from the hinge that the reader does not see the hinge coming from it, and close enough to remember it when it comes.
The second condition is the price. The old criterion must be seen to cost something before the hinge, and the hinge must give up something the old criterion valued. The first cost is often concentrated in what James Scott Bell, in a manual already used in The Middle (Chapter 11), calls the mirror moment: a scene near the middle in which the character sees what they have become. In arc terms it is the scene in which the old rule produces a result the character would condemn in someone else. The second cost is the price of the hinge itself, and it is what makes the decision a decision: a change that costs nothing under the old rule is the free hinge of Failure Patterns.
The third condition is the hinge itself: a decision, on the page, under pressure, made by an act rather than a statement. The act can be small. It must be one the character could not have performed under the old rule, and the reader must be able to see the alternative being declined.
The fourth condition is enactment: the new rule must be confirmed after the hinge by a choice in a situation the book has shown before, answered differently, against something that has not changed. The Ending (Chapter 16) calls the unchanged element the constant, and an arc without one reads as replacement, since a character who is different in every respect has been swapped for another rather than developed. The constant is often the character’s manner, their habit of attention or their want, carried unaltered into a decision made for a new reason.
Where the conditions fall
The conditions have conventional positions, which follow from what each needs. The seed falls early, often in the first quarter, so that it can be forgotten and recalled. The mirror moment tends towards the centre of the book, where The Middle (Chapter 11) places the midpoint’s change of mode or knowledge, and this is not a coincidence: a midpoint that changes what the protagonist knows is often the moment the old rule is first seen to cost. The hinge falls at or just before the climax, because a criterion is tested hardest when the options have narrowed to one move and the old rule forbids it. Enactment falls in the aftermath, where The Ending’s domain of character-arc completion (Chapter 16) lives. These are conventions of placement, not requirements, and a book that hinges early must find something else to carry its second half.
The answer map
The theme has its own tool, which reads the same decisions from the other side. The answer map writes the book’s thematic question at the top, and beneath it, for each major character, the criterion by which they choose, rewritten as that character’s answer to the question. Three readings follow. If every character answers the same way, the book has a sermon rather than a theme. If the opposition’s answer is one the book never lets succeed or cost anything, the variation is a straw figure. And the protagonist’s hinge can be located on the map: the new criterion adopts another character’s answer, combines two, or finds one no character held. The last is the strongest and the hardest to seed.
Multiplicity at the hinge
A hinge scene usually serves three of the domains The Purposes of a Scene (Chapter 1) sets out at once. It moves the plot, since the decision changes what happens next; it completes or turns the arc; and it delivers the book’s verdict on its question, since the reader weighs the new answer against the answers the map has shown. A hinge that serves character alone, a scene of interior change that the plot does not need, tends to read as inserted. In the household revision in Worked Analyses, Elena’s decision not to open the ledger until her sister is in the room delays the plot by a page, completes her arc and gives the book’s answer to its question, with no sentence of statement.
See also: the full treatment, with a blank criterion log and answer map, and the household’s log and map in full.