Who knows what, when

Every story with a secret in it has a second story running underneath: the story of who knows the secret, and when they found out, and who they have not told. The reader is a character in that second story. So is the narrator. And the second story is where the errors live that no amount of rereading catches — the scene in Ada's point of view that mentions the pawnbroker's name a chapter before anyone tells her; the moment Ned acts on something only the reader has seen; the mystery whose solution rests on a clue that was, it turns out, never on the page.

Readers catch these. They cannot always say what is wrong, but they feel the floor shift, and they trust the book a little less from that point. Writers almost never catch them, because a writer knows everything, all the time, and cannot un-know it while reading their own chapter twelve.

The method for this is bookkeeping, and it is very old — the mystery writers of the 1920s kept it in notebooks. A ledger of facts, a row of scenes, and a mark for each person at the moment they learn each thing. You do not need any software. If you use software, the steps are the same.

The facts

First, a card for each thing that can be known. Not every fact in the book — the ones that are withheld from someone. In Ada's story:

• Tomas is alive.
• Tomas took the money.
• The locket was their mother's.
• Ned works for the harbourmaster.
• Ada told the neighbors a lie, for a year, when she was eleven.

Eight or ten of these is typical for a novel with a secret; a mystery might have twenty. Each is a card with the fact as its title, in a sentence, true within the story. If you are not sure whether something belongs on the list, ask: is there a scene in which a character does not know this and it matters that they do not? If yes, it is a fact card.

The ledger

Now a grid. Fact cards down the left. Across the top, every person who could know each fact — and the reader, as a column of their own, because the reader knows only what the page has told them and forgets nothing.

Go through the scenes in order. Each time someone learns a fact, write the scene's number in their cell for that fact. Ada learns Tomas is alive in scene 9, from the pawn ticket. The reader learns it in scene 9 too — unless you showed Tomas in scene 4, in which case the reader has known for five scenes what Ada has not.

Four kinds of mark, because there are four ways of coming to know a thing:

• learns — the ordinary case: it is shown or told and they believe it.
• suspects — they have the thought and cannot confirm it. Half of a thriller's tension lives here.
• is told falsely — they now believe something untrue. Mark what they were told, and by whom; the cell is a lie with a scene number.
• forgets — rare, and useful in exactly the stories that need it.

The ledger takes an hour for a novel. It is the hour that finds the errors.

Reading it

A scene through someone's eyes that contains what they do not know. Scene 7 is in Ada's point of view, and Ada's narration mentions the pawnbroker on Fell Street. Look at the ledger: Ada learns of the pawnbroker in scene 9. Scene 7 is a leak. Either she learns it earlier — and that is a new beat, and the ledger tells you where it can go — or the mention comes out. This is the error readers feel most and name least, and it is invisible to the writer without the ledger, because the writer has known about Fell Street since the outline.

Someone acting on what they have not been told. In scene 15, Ned steers Ada away from the harbourmaster's office. The reader knows why: Ned works there. Ada does not. But the ledger says Ned learns Tomas took the money in scene 18 — so in scene 15, Ned is protecting Tomas from a thing Ned has not yet found out. A continuity error, of the kind no reread catches, because it is not a contradiction on any single page. It is a contradiction between two pages sixty apart.

The gap between the reader and the character. Read across the reader's column and Ada's, fact by fact. Where the reader knows and Ada does not, the scene is running on dramatic irony — the reader watching her walk toward the thing they can see. Where Ada knows and the reader does not, the scene is running on withheld narration, which is harder to do honestly and which readers resent when they discover it. Both are legitimate. Both should be chosen. The ledger is where you find out which you have been doing by accident.

The fair-play check. For a mystery: take the solution — Tomas took the money, and hid it in the locket — and list the clues a reader would need to reach it. Now find each clue in the reader's column. Is every one of them marked, at a scene before the solution? If one is not — the locket's false back was never shown, or was shown in scene 31 and the solution comes in scene 30 — then the reader could not have solved it, and the whole promise of the genre was broken in a way that no one in the room noticed. This one check is the entire craft anxiety of the mystery, and it is a column and a list.

The reveal as a card

Each moment where a fact is disclosed is a scene beat, and it deserves its own card: what comes out, and who finds out — the reader, a character, or both. Put it in the row of scene cards where it lands. A reveal that discloses to the reader and not to the character opens a gap; a reveal that discloses to the character and not the reader closes one from the other side. Both are marks in the ledger, and the reveal card is where the mark comes from.

The reveal card also has a use the ledger does not. Guide 18 said a character's false belief needs a moment in which it breaks. That moment is a reveal to her: the disclosure of a fact — keeping the story straight is how people get hurt — that she has resisted knowing. Link the reveal to the character whose lie it breaks, and the character card and the ledger agree on when she changed.

What the ledger is not

It is not the plot. It records who knows what; it does not record what happens. A fact can be known by everyone and still matter, if what they do about it differs.

It is not for every book. A novel with no secrets does not need it. A novel with one secret needs one row. The method scales to the story; a literary novel about a marriage may have three facts on the ledger and be transformed by keeping them straight.

It is not the misdirection. A red herring is a thing the reader is meant to believe that is not true, and it belongs in the ledger as is told falsely — in the reader's column, with the scene, and beside it a note of what is really true. That way the pass over the ledger, yours or a machine's, does not mistake a deliberate lie for a broken promise.

Doing this in software

Software built on cards can keep the ledger inside the cards: on a fact card, or a reveal card, a list of who learns it and where — a name, or the reader, and the scene, and which of the four kinds of knowing. From that, the same grid the table showed: threads of knowledge across the scenes, and a band on the plot grid for each scene showing how many facts the reader holds there that the viewpoint character does not — dramatic irony, drawn.

And the errors become sentences the software can say when asked, without judging the story. This scene is through Ada's eyes, but it mentions something Ada doesn't know yet: the pawnbroker on Fell Street. Ned is in this scene, and it turns on something the reader knows that he hasn't found out yet. The reader never saw the clue that solves this: the locket's false back. They can't play along. The reader only gets this clue after the answer it points to. This steers the reader away from the answer, and the card doesn't say what's really true.

The software can only check the facts you put on cards; the ledger is as complete as you make it, and a fact you never wrote down cannot leak. But that is the same on paper. What the software adds is that the check runs every time a scene moves or a card changes, and says its one sentence, and the sentence points at a scene. Whether the leak is a leak or a deliberate glimpse — whether you want the reader five scenes ahead of Ada — is a decision the ledger cannot make and was never meant to.