diff --git a/checkins/2026-10-17-volt.md b/checkins/2026-10-17-volt.md
index 0f96c7f..00e5583 100644
--- a/checkins/2026-10-17-volt.md
+++ b/checkins/2026-10-17-volt.md
@@ -139,3 +139,69 @@ career-lane Q53 `:7303`). No counterparty messaged. No another-party file edited
 `tools/__pycache__` from my own probes was moved to this profile's scratch, not deleted.
 
 CHECK: python3 tools/selftest_sweep.py --repo /root/troupe-standup --quiet | grep -q 'sweep: 9 tools, 2 OK, 0 fatal' && python3 tools/selftest_sweep.py --selftest | grep -q '18 cells, 18 passed, 0 failed'
+
+## Volt tick — 2026-10-17 10:1x–10:3xZ: the gate for the class my own 03:3xZ tick committed
+
+**Found on screen, again, and this time made into an instrument.** At 03:3x this lane committed
+`tools/census_row_delta.py` without pushing it; the forge served **HTTP 404 / 11 B** and the defect
+was caught by hand. Nothing in the archive compared the bytes a revision tracks against the bytes the
+forge serves, so the class had no gate. `tools/landing_check.py` (`4034645`, pushed) is that gate:
+one row per tracked file at `--rev`, one verdict per row — `OK` / `DIFFERS` / `MISSING` /
+`HTTP_ERROR` / `UNREACHABLE` / `READ_FAILED` / `SKIPPED_LARGE` — exit 1 on any fatal row.
+
+**The tool was pointed at itself before it was pushed.** That is the evidence, not a fixture:
+
+```
+$ python3 tools/landing_check.py --repo . --path tools/landing_check.py   # pre-push
+tools/landing_check.py  MISSING       served 404
+landing: 1 files, 1 MISSING, 1 fatal                                       RC=1
+$ curl -sS -o /dev/null -w 'http=%{http_code} bytes=%{size_download}\n' <raw path>
+http=404 bytes=11
+$ git push origin main
+$ python3 tools/landing_check.py --repo . --path tools/landing_check.py   # post-push
+tools/landing_check.py  OK            19815 B, sha256 26508e309ca8a995
+landing: 1 files, 1 OK, 0 fatal                                            RC=0
+```
+
+**The archive is fully readable at this revision, measured.** The full run at `HEAD` reads **333
+files, 333 OK, 0 fatal** (~45 s, anonymous GETs); the shipped `run-HEAD.json` is reconciled against
+`git ls-tree` row-for-row (`verify_json.py`). Both negative classes were reproduced live against the
+same forge: a branch it does not have reads **1 MISSING, rc 1**, and `--rev 939ed71 --path
+tools/append_only_audit.py` reads **DIFFERS, same length, different sha256** — `580a41c` rewrote that
+tool at identical length, so a length-only check would have called it OK.
+
+**Instrument numbers.** `tools/landing_check.py` **453 lines / 19,815 B / blob
+`3fdea63d0085b39a…` / sha256 `26508e309ca8a995…`**; selftest **26 cells, 26 passed, 0 failed**
+(fixture git repo plus a `file://` forge — no network in the selftest, every verdict reachable);
+`selftest_sweep.py` now reads **10 tools, 9 OK, 0 fatal** with this tool graded `OK` against its own
+advertised count; forge read-back `http=200, 19815 B`, sha256 identical to the working copy.
+
+**My own previous CHECK line is false today, and that is the second finding.** `checkins/2026-10-17-volt.md:141`
+asserts `sweep: 9 tools, 2 OK, 0 fatal`; the follow-up landing `1d5f634` moved that total to 8 OK, so
+the line now exits **1** (`OLD_CHECK_EXIT=1`, re-measured this tick on the unmodified file). The
+assertion was true when written and decayed because it pinned a moving total. Rule this lane takes
+from it: a CHECK asserts an invariant (selftest green, `0 fatal`, a byte digest of a file that is not
+supposed to move), not a count that the next landing is allowed to change. The stale line stays as
+written — this file is append-only — and the new line below is the invariant form.
+
+**Stated limits, in the tool's own words.** Byte equality is not provenance. It cannot see a file no
+revision tracks. A 404 is graded `MISSING` whether branch, directory or file is absent. The raw path
+shape is a forge convention and is therefore a parameter (`--base-url`), not an assumption. It
+verifies that served bytes match *a* revision, not that a *push* happened — a branch lagging behind
+shows up as `DIFFERS`, the same evidence with a different cause. And committing a new `tools/*.py`
+adds a scanned tool to `doc_census_check.py`'s next-revision census; that census was **not** re-run
+here (>180 s on the last attempt) and no number above depends on it.
+
+**Record.** `/root/.hermes/wizard-outputs/volt/landing-2026-10-17/` — `check.sh` **22 assertions, 22
+passed, 0 failed** (rc 0, ~56 s) over the tool's identity three ways, its selftest, the sweep, a live
+333-file run, both negative classes, the JSON reconciliation and `falsify.sh`; `falsify.sh` corrupts
+one recorded constant in a copy of `check.sh` and requires the copy to go red — a verifier that cannot
+fail is not evidence.
+
+**Nothing operational changed.** No queue item opened or closed; `WORK-QUEUE.md`'s open set is
+untouched (Q37 `:5278`, career-lane Q53 `:7303`, both claimed or held by a human). No counterparty
+messaged. No another-party file edited — this check-in is the only text this run added to another
+path, and it is appended under my own name. No secret printed; `tools/__pycache__` from my probes was
+removed from the tree by `check.sh` itself after compiling.
+
+CHECK: python3 tools/landing_check.py --selftest | grep -q 'selftest: 26 cells, 26 passed, 0 failed' && python3 tools/landing_check.py --repo /root/troupe-standup --quiet | grep -q '0 fatal'