Your pages, kept.
Your novel, finished.
Paste the chapters you have. ExpandArc maps them, finds the plot holes, and expands the arc beat by beat — every passage you wrote preserved, every change approved by you.
- Nothing you wrote is dropped
- Zero continuity errors
- Your tone, every sentence
The control room breathed in the dark. Mara counted the strobes — one red pulse every four seconds — and used the gaps to move, because the light showed everything and the dark showed her.
Coolant dripped somewhere behind the server racks, patient as a clock. Her left shoulder had stopped complaining and started lying to her about it, which was worse.
Critic · 9/10
0 details lost
Ledger
2 changes proposed
Author Gate
Approve · Revise
Ledger · Mara · after beat 7.3
- statusleft shoulder = bruised
- inventorykeycard = lost
- knowsreactor sabotaged
Chatbots write chapters.
Books need architecture.
Generative AI fails at long books because it lacks persistent memory, forgets plot constraints, leaks secrets characters should not know yet, rushes pacing — and, worst of all, rewrites what you already wrote. ExpandArc separates story structure, world memory and prose drafting into specialised steps, and treats your text as the thing to build on, not replace.
The pipeline
From your pages to a finished book, one verified stage at a time
Blueprint
Your manuscript or outline, cast, world rules and the twists you want to land — auto-filled from your text if you like.
Plot Audit
The story doctor lists the holes — motive, causality, setup without payoff, timeline — asks you one question each, and offers a fix.
Treatment
A chapter map over your scenes plus the gaps that need new material. You verify the shape before a word is drafted.
Roadmap
Each chapter becomes beats of 300–600 words: preserve your passage, expand around it, or bridge a gap.
Studio
Drafts stream in. The Critic checks continuity, secrets and fidelity to your text. You approve, revise, or restore your wording.
Living Ledger
Injuries, inventory, location, who knows what — recorded after every beat so later chapters inherit the facts.
Your passage
The rain came in the second week of October. A man in a torn suit stood at the gate. He did not press the intercom.
Polished into your tone
The rain came the second week of October. A man in a torn suit stood at the gate and water pooled at his cuffs. He did not press the intercom.
Expand mode
Your text is canon
Every passage you paste becomes a scene the system may polish or build around, never summarise away. A word-level diff shows exactly what changed; the Critic fails any draft that loses a name, a number, a line or an image from your original. One click restores your wording.
- Preserve — your passage, in your chosen tone, nothing cut or added.
- Expand — your passage kept whole, new material built around it.
- Bridge — new scenes only where the arc has a gap.
Director Mode
It does not feel like prompting. It feels like directing.
- You supply the vision: your pages, your cast, the twists you want to land.
- ExpandArc structures the plan and shows every decision for your sign-off.
- You watch the story construct in real time — directing each beat, approving each state change.
Briefing packet · Ch 7 · Beat 3
- POV
- Mara Vance — exhausted, left shoulder bruised, no keycard
- Goal
- Discover the sabotage without triggering the second siren
- Senses
- Ozone, red emergency strobe, coolant dripping behind the racks
- Must not surface
- Mara does not know Idris planted the device (known only to Idris)
- World rule
- Airlocks cannot open while the reactor is above 40% load
- Your direction
- Keep her silent until the siren. One line of dialogue, no more.