The instruments in this chapter assume that a middle should narrow. The option list, the midpoint test and the clock are calibrated to books that move towards a single end, and they will report as failures the contained and episodic middles of a serious body of fiction that prefers duration to direction: The Magic Mountain, The Rings of Saturn, the picaresque. When they do, the model is reporting its own assumption, and the exceptions in Failure Patterns show what such books put in place of narrowing, a repetition that is itself the argument or a constant that is itself an engine.
For most novels the assumption holds, and it has a consequence that is easy to state and hard to accept. The ending is where a book’s shape becomes visible, but the middle is where it is decided. Whether an ending reads as inevitable or arbitrary depends on how many moves the middle left open, and whether the climax lands depends on what the middle made it cost. A writer who revises the ending of a book whose middle never narrowed is repairing the wrong part, which is why The Ending (Chapter 16) sends its hardest diagnosis back here.
That is also the answer to the complaint the chapter began with. A middle that drags is rarely short of event, and adding event treats the symptom. The remedy is to ask of each sequence what it takes away from someone, and to cut or rewrite the ones that take nothing. The household draft is the chapter’s evidence that this is usually a matter of arrangement rather than invention: its revision cut three sequences, and everything it added came out of the sale the draft already contained, moved to where it closed a move for someone.
See also: the full treatment, on the limits of the model and the forms of middle it does not describe; The Structural Edit (Chapter 18), which puts the option list into a revision order for the whole book.