Planning an arc

The story bible records what has happened and a character design records who someone is meant to become. An arc is the level above both: the shape of a stretch of the book, anywhere from ten chapters to a hundred.

It is off by default. Turn it on in novel settings, per novel.

An arc owns chapters

Every arc has a range, and the range is the point — it is what lets the app know which chapter belongs to which plan. You can put an arc behind you: if you are on chapter 30 and arc one was chapters 1–20, say so, and arc two starts at 21. Planning then begins at 31, and the ten chapters you have already written go to the planner as context rather than being planned again.

Ranges are elastic. Writing past the last chapter of an arc is allowed and simply says so, with an offer to extend it. Nothing about a plan ever stops you writing.

1. Describe it

Write what the arc is about in whatever shape suits you — four lines, a paragraph, a list of things that must happen. Vagueness is fine here: “somewhere in here he has to choose between delivering the ledger and burning it” is a real intention and it will be kept as one.

2. Refine it

Refining reads your description against your story bible, your character designs and the chapters already written, then hands back a tightened description and the beats it breaks into. Every beat is marked yours or added, and what you originally wrote is kept — one click puts it back.

That marking is not decoration. A plan you cannot tell apart from your own thinking is one you have to re-read rather than lean on, so nothing the assistant writes is ever left looking like yours.

Chapters cannot be planned until this has happened, deliberately: a plan generated from three vague lines is fifty vague chapters, and you would only find that out by reading all fifty.

3. Plan the chapters

Ten at a time, arriving one by one as they are written. Each planned chapter carries what it opens on, what turns in the middle, and where it lands — enough for a real chapter rather than a topic. “Rennick investigates the ledger” is a label; “Rennick reads the first page, recognises his own city’s debt, and re-seals it before the clerk returns” is a chapter.

Each also carries a tag or two — political, betrayal, downtime, flashback — chosen for what is most distinctive about the chapter, so fifty of them stay scannable.

Editing, by hand or by asking

Every chapter can be edited directly, or rewritten by instruction: “make the confrontation happen off the page”. An AI edit touches only the thing you pointed at, and keeps what it replaced so you can see the change. The same works on the arc description itself.

Edits are canon. The next ten chapters are planned from what your chapters now say, not from whatever was originally proposed.

Writing from the plan

When a chapter has been planned, the composer offers it instead of the three directions — there is no point proposing alternatives to something you already decided. Using it fills the box as editable text, and nothing is written until you send it.

Steering, and how gentle it is

An arc can optionally be steered, which puts a few lines into every chapter prompt about where the story stands in the arc. It never names an upcoming beat — the writer is not shown your later chapters at all, which is the only reliable way to stop chapter 40’s reveal turning up in chapter 30 as “setup”. Foreshadowing is allowed only where a scene already invites it, and advancing the arc is never required.

When the story leaves the plan

It will, and that is usually the story working rather than failing. Nothing is checked automatically and nothing nags: when you want the rest brought back into line, re-plan it, and what you have actually written becomes the context it plans from.

What it costs

Planning runs on a stronger model than the other helpers here — a cheaper one starts inventing characters once it is asked for chapters with real substance in them. Even so, a fifty-chapter arc plans for a few cents, billed to your OpenRouter key like everything else. If a plan does introduce a name your story bible has never heard of, it is flagged on that chapter rather than slipped in quietly.