Deep Reader

Read long books and papers the way a careful human researcher does: skim for structure first, read deeply chapter by chapter with notes as you go, then synthesize from the notes — never the raw text — at the end. The method comes from Adler's How to Read a Book, SQ3R's Recite step, and Keshav's three-pass method for papers.

Why multi-pass, why notes

An LLM's attention dilutes over long contexts, and it loses track of material buried in the middle of a big prompt ("lost in the middle"). Loading a 500-page book into one context and asking questions about it produces answers that quietly forget chapter 3 by the time you're discussing chapter 12.

The fix is the same one human researchers use: never hold the whole book in working memory at once. Read it in passes — first for structure, then chapter by chapter for content — and externalize what you learn into note files as you go. The notes become the durable memory; the book itself only needs to be back in view when you're actively reading a specific chapter or verifying a specific claim. Page numbers are the coordinate system that makes every claim traceable back to the source, in this session or a later one.

Two modes

• overview — Adler's inspectional pass only: a book map plus a goal-directed summary of the chapters that matter most to the reader's purpose. Fast, no per-chapter notes.
• study — the full pipeline: reading purpose → inspectional map → chapter-by-chapter analytical notes with Recite verification → hierarchical synthesis answering Adler's four questions → mechanical quote verification.

The user picks (or you propose one from mode_hint + their stated purpose — see Step 1).

Workspace layout

Everything the pipeline produces lives in a workspace directory, by default a sibling of the source file, so it survives across sessions:

<slug>-notes/
├── source.txt          # full text with [[page N]] markers — the coordinate system
├── chapters.tsv        # confirmed structure: chNN<TAB>from<TAB>to<TAB>title
├── chapters/           # per-chapter files cut by split-chapters.sh
│   └── ch01-<slug>.txt
├── map.md              # inspectional pass output
├── terms.md            # key-terms ledger, cross-chapter
├── notes/
│   └── ch01-<slug>.md  # one analytical note per chapter (papers: sec01-<slug>.md)
└── synthesis.md        # final synthesis + verification log

This workspace, not the SKILL.md scripts, is what makes a later session able to answer a follow-up question without re-reading the book (see "Answering from existing notes" below).

Scripts at a glance

All seven scripts live in scripts/ under this skill. Run them either as bash ./scripts/<name>.sh ... from the skill directory, or as bash /mnt/skills/user/deep-reader/scripts/<name>.sh ... on claude.ai — both forms invoke the same script, use whichever matches where you're running.

Step 0 — Prepare

Locate the source file, then convert and page it:

bash ./scripts/prepare-text.sh path/to/book.pdf
# or on claude.ai:
bash /mnt/skills/user/deep-reader/scripts/prepare-text.sh path/to/book.pdf

This is idempotent — re-running it on a workspace that already has source.txt reports existing stats instead of reconverting, so it's safe to call at the start of every session on the same book.

Read the JSON it prints. pages and est_tokens tell you the book's size; mode_hint gives a starting recommendation (small/medium/large); if synthetic_pages is true (EPUB/DOCX/TXT/MD sources have no real page numbers) remember that page citations in notes still point into source.txt's own paging — verifiable, just not the printed page numbers a reader with the physical book would see.

Two branches before you go further:

• A workspace with notes already exists for this book (check <slug>-notes/notes/ for files) — skip straight to "Answering from existing notes" below instead of restarting the pipeline.
• Exit code 2 (missing pdftotext/pandoc) — fall back to reading the PDF/EPUB directly with the Read tool in page batches. You lose verify-quotes.sh's mechanical check in this fallback; compensate with more frequent manual re-reads of anything you quote.
• Scripts misbehaving? Run bash ./scripts/self-test.sh — it distinguishes an environment problem (missing/broken dependencies) from a usage problem.

Step 1 — Reading purpose

If the user hasn't said why they're reading this book, ask one question: "What do you want out of this book?" Purpose isn't a formality — it decides which chapters get a deep pass and which get skimmed, and it's the yardstick Step 4's synthesis is judged against.

Once you know the purpose, propose a mode using mode_hint plus that purpose (e.g. a 40k-token book read for one narrow question can stay in overview even though it would technically fit; a 200k-token book read to write a literature review needs study mode regardless of size). Let the user confirm or override.

If the source is a paper, thesis, or survey rather than a book, read references/paper-mode.md now — it maps Keshav's three-pass method onto this same pipeline and tells you when the full workspace apparatus is worth the overhead versus when passes 1–2 belong inline in the conversation.

Step 2 — Inspectional pass (both modes)

Build a seed, then confirm it against the real book:

bash ./scripts/extract-structure.sh <workspace>/source.txt

Treat its output as a noisy first guess, not ground truth — cross-check it against the table of contents. Then:

1. Use read-pages.sh on the table of contents, preface/introduction, conclusion/final chapter, and index if present.
2. Skim first and last paragraphs of 2–3 sampled chapters.
3. Write map.md using the template in references/note-templates.md.
4. Once map.md's classification field is filled in, read the matching section of references/genre-strategies.md before starting the analytical pass — practical books, imaginative literature, history, science and math, philosophy, and textbooks/reference works each shift the reading in ways that are cheap to apply up front and expensive to retrofit into notes you've already written.

With the structure confirmed, make it durable and cut it into pieces:

# id  from  to  title  — one line per chapter, tab-separated
printf 'ch01\t9\t34\tThe Activity of Reading\n' > <workspace>/chapters.tsv
bash ./scripts/split-chapters.sh <workspace>/source.txt <workspace>/chapters.tsv
bash ./scripts/build-diagram.sh <workspace> --append

split-chapters.sh gives every chapter a self-contained file — useful for the analytical pass and essential if you fan out to subagents. build-diagram.sh --append drops a Mermaid mindmap of the confirmed structure into map.md under a ## Structure diagram heading; it's re-runnable without duplicating the block.

Overview mode stops here: deep-skim only the 2–4 chapters most relevant to the reading purpose (openings, closings, key sections), extend map.md with a goal-directed summary, present it to the user, done. No per-chapter notes, no synthesis, no verification pass.

Study mode continues to Step 3.

Step 3 — Analytical pass (study mode)

Loop over chapters in chapters.tsv order. If the book is composed of many micro-chapters (1–10 pages each), don't write one note per micro-chapter — group them by the author's own part/section divisions instead. The target is one note per coherent argument unit, not one per heading; a 67-chapter book might correctly merge down to 16 part-level notes. For each resulting unit:

1. Read the chapter — from chapters/chNN-*.txt, or read-pages.sh / Read-tool in batches if you skipped splitting.
2. Write notes/chNN-<slug>.md using the template in references/note-templates.md: the question this chapter answers, key terms (also mirror each into the cross-chapter terms.md ledger), leading propositions, arguments (premises → conclusion), evidence offered, quotes with (p. N), tensions or links to other chapters, and open questions.
3. Recite (the SQ3R step): with the note drafted, re-skim the chapter and check every proposition and quote against the text before moving on. Fix the note now, while the chapter is still fresh — not later during synthesis. Once the note passes this check, let the chapter leave working memory; the note is the memory from here on.

Fan-out option: if subagents are available and mode_hint flagged the book as large, you may spawn subagents instead of looping sequentially. Group chapters into batches per subagent — balance each batch's word count rather than assigning strictly one chapter each — and give each subagent: its batch's page range(s), the reading purpose, the note template path, and the scripts path. Have each subagent return its terms.md rows in its final message rather than writing them directly, so you (the orchestrator) merge all contributions into terms.md centrally — parallel subagents writing the same file directly is a race. You keep ownership of map.md, the merged terms.md, and the Step 4 synthesis — don't delegate those. Sequential reading is the default and works everywhere; fan-out pays off even when subagents can't run in parallel, because the benefit is context isolation — each batch gets a fresh context window — not just speed.

Step 4 — Synthesis

Read the notes now — not the book. Write synthesis.md answering Adler's four questions, each claim carrying a page cite:

1. What is the book about as a whole?
2. What is being said in detail, and how?
3. Is it true, in whole or in part?
4. What of it? — answered specifically against the user's stated reading purpose, not in the abstract.

Alongside the four questions, hand-author a Mermaid graph — a concept and argument map showing which key terms and propositions feed which conclusions, across chapters — built from terms.md and the chapter notes. This is intelligence work, not mechanical: it's the argument-level counterpart to the structural mindmap build-diagram.sh drew in Step 2, and no script can produce it because it requires judging which ideas actually depend on which.

Step 5 — Verify

Run the mechanical check first:

bash ./scripts/verify-quotes.sh <workspace>

For every FAIL or NEAR line, re-open the cited pages with read-pages.sh and fix either the quote text or the page number, then re-run until it exits 0. This catches fabricated quotes and off-by-a-page citations, but it can only check quotes — it can't check paraphrase.

So finish by hand: pick the 5–10 most load-bearing paraphrased claims in synthesis.md and re-verify them by targeted re-reading of the cited pages. Mark each ✓ verified in a short verification log at the bottom of synthesis.md, per the template.

Answering from existing notes

In a later session, or mid-session after synthesis, don't re-read the book to answer a question. Search the workspace first — grep across terms.md and notes/ — and answer from what's there. Only when the notes don't cover the detail, follow the page anchors they carry into source.txt with read-pages.sh or search-book.sh. The whole point of the workspace is that one follow-up question shouldn't cost a full re-read.

Critical judgment

Adler's etiquette for the "is it true" question: don't judge before you can fairly restate the author's position — that's exactly what the Recite check in Step 3 is for. Then keep three verdicts distinct:

• "The author is wrong here" — backed by page-cited reasons.
• "The author is incomplete" — a gap, not an error.
• "I cannot verify this" — say so rather than guessing.

Disagreement without a page-cited reason isn't criticism, it's opinion — don't present it as the former.

Syntopical reading

For a question spanning multiple books or papers, run the pipeline once per work — each gets its own workspace and synthesis.md. Then write a comparative synthesis across those synthesis.md files: where the works agree, where they conflict, and a neutral terminology for the shared topic that doesn't privilege any single author's vocabulary.

Communication

Work in the language the user used to ask. The deliverable is the synthesis (or, in overview mode, the goal-directed summary) placed directly in the conversation — the workspace files are the durable byproduct, worth pointing to but not a substitute for answering in-chat.