The instruments in this chapter assume a reader who arrives with a horizon, not a blank page, and who reads a book as an answer to the expectations she brought to it. The promise inventory records what the book asks her to expect; the volume table records what a series asks her to keep expecting across the gaps between books. Both describe a reader for whom a convention is not a rule a writer obeys but a promise she was made, and who judges a book less by what it pays than by whether it paid what it said it would. That a book can decline a genre’s central payment and satisfy its readers, as Northanger Abbey and The Leftovers do, is evidence that the reader’s contract is with the book’s declarations, not with the genre’s rules.
That is the chapter’s argument. A genre is a set of promises a writer inherits and a series a set of promises she makes for later, and each is kept or broken by the text, not by the shelf. A convention may be kept, varied or declined, and the third is as legitimate as the first, on two conditions: that the book says so early, inside itself, and that it puts something in the declined promise’s place and keeps that. A volume of a series may leave much open, on one condition: that what it leaves open is the series’ question and not its own.
The household revision illustrates the economy. It removed a last page and a sentence of jacket copy, and found that the book had declared its kind three times, each by a character deciding not to ask, and that the question it declines is the one its subject requires it to leave open.
See also: the full treatment, section 8, on the limits of the model; The Structural Edit (Chapter 18), which puts the promise inventory into a revision order for the whole book.