diff --git a/README.md b/README.md
index 9fa44fc..0ef5060 100644
--- a/README.md
+++ b/README.md
@@ -22,9 +22,12 @@ Lean 4 against models extracted from the actual Rust sources:
 
 ## The book
 
-**[`main.pdf`](main.pdf)** — twelve chapters + interlude + three
-appendices, 106 pages, full color, built with LaTeX/TikZ from the sources
-in this repo. No prior Lean or formal methods assumed; high-school algebra
+**[`main.pdf`](main.pdf)** — thirteen chapters + interlude + three
+appendices, full color, built with LaTeX/TikZ from the sources in this
+repo. **Honesty note:** the committed PDF (109 pages) was built 2026-07-06,
+before chapter 13 was committed (2026-07-28) — rebuild with the command
+below to get the current book; the committed PDF lags the committed
+sources until the next rebuild on a LaTeX-equipped machine. No prior Lean or formal methods assumed; high-school algebra
 and a little programming suffice.
 
 1. **Why Verify?** — the carry bug testing cannot find
@@ -40,6 +43,7 @@ and a little programming suffice.
 10. **Verifying a Field** — the full campaign, told honestly (including the crash)
 11. **Honesty and Axioms** — `#print axioms`, hollow certificates, trusted bases
 12. **The Pyramid** — group law, scalars, signatures, and where you come in
+13. **The Attestation Protocol** — what it takes to make "it is proven" checkable by a stranger
 
 Appendices: **A** — the pen-and-paper toolkit (recipe cards with drills);
 **B** — guided walkthroughs of every exercise-file hole; **C** — a tour of
@@ -118,10 +122,12 @@ In the spirit of Chapter 11:
   twice (mod-13 sign-bit walk, then the real compressed base point:
   byte-31 sign bit, and the full-size hand verification 5·y_B − 4 = 4·p,
   every digit printed), plus a new paper exercise (12.4). Every printed
-  constant was machine-verified before typesetting; the PDF (109 pages)
-  is rebuilt from these sources.
+  constant was machine-verified before typesetting; the PDF (109 pages,
+  2026-07-06 build — predates ch13) is rebuilt from these sources.
 - The PDF in the repo is built from the committed sources by the command
-  above; rebuild it yourself if you don't trust binaries (good instinct).
+  above — but the committed build currently predates chapter 13 (see the
+  honesty note at the top); rebuild it yourself if you don't trust binaries
+  (good instinct), and you will get the thirteen-chapter book.
 - The three named solution certificates were kernel-audited
   (coherence pass 2, 2026-07-03): `Ch09.add_spec` depends on
   `[propext, Classical.choice, Quot.sound]`; `Ch09.mulVal_spec` and
diff --git a/chapters/appendix-walkthroughs.tex b/chapters/appendix-walkthroughs.tex
index 6a02d82..2284727 100644
--- a/chapters/appendix-walkthroughs.tex
+++ b/chapters/appendix-walkthroughs.tex
@@ -171,7 +171,9 @@ actually wrote.
 
 \medskip
 \noindent That is the last hole in the last file. If you worked them
-all: the companion repositories' open scalar-layer lemmas are shaped
-exactly like 9.B --- bigger constants, same bones --- and the
-\code{CONTRIBUTING} notes there will treat you as what you now are:
-someone who has done this before.
+all: the scalar layer that was open when this appendix was first written is
+now complete on all four companion forks (thirteen certificates each ---
+lemmas shaped exactly like 9.B, bigger constants, same bones). The open
+frontier today is the paused Pasta curve layer, and chapter 12's ``Extend
+the pyramid'' item points at it; the \code{CONTRIBUTING} notes there will
+treat you as what you now are: someone who has done this before.
diff --git a/chapters/ch10-verifying-a-field.tex b/chapters/ch10-verifying-a-field.tex
index b5045a2..b8e0980 100644
--- a/chapters/ch10-verifying-a-field.tex
+++ b/chapters/ch10-verifying-a-field.tex
@@ -225,7 +225,9 @@ A verified fork is verified \emph{at a commit}. Change one line of
 arithmetic and the certificate is stale --- that is a feature (the proof
 \emph{should} break when the code changes), but it means verification is a
 \emph{process wired into maintenance}, not a trophy. The companion repos
-ship \code{check.sh} scripts that re-extract and re-verify from scratch;
+ship \code{check.sh} scripts that recompile and re-audit every shipped
+proof from scratch (extraction replay is a separate pinned recipe,
+\code{verification/extract.sh});
 treat those as the project's pulse, not as CI decoration.
 \end{pitfall}