diff --git a/docs/content-model.md b/docs/content-model.md
index 3b2e588..8b22bc2 100644
--- a/docs/content-model.md
+++ b/docs/content-model.md
@@ -1,5 +1,30 @@
 # Content model
 
-- Canon units: parsed headings with stable IDs, line ranges, and SHA-256 hashes.
+## Canon hierarchy
+
+Canon units are parsed headings with stable IDs, line ranges, SHA-256 hashes, major-section membership, and immediate heading-parent relationships.
+
+The opening hierarchy is load-bearing:
+
+```text
+Awakening
+The Interdefinables
+  Human consciousness emerges from
+    Binary essences...
+    Trinary perceptual focal states...
+    Trinary states of social perception...
+    Archetype passions of possession...
+Preamble
+Rights and Definitions of The Way
+```
+
+`Human consciousness emerges from` is not a peer section. It is a subheading beneath `The Interdefinables`; its binary, trinary, and archetype headings are nested beneath it. `Preamble` is the next major section after `The Interdefinables`.
+
+## Other records
+
 - Project records: public GitHub facts plus visible `hmmm` when editorial metadata is missing.
 - Lab records: generated per canon unit, with reviewed research gaps explicitly shown.
+
+## Usage guidance
+
+Run `npm run validate` after a canon refresh. The validation gate rejects a build that promotes `Human consciousness emerges from` to a section, assigns it outside `The Interdefinables`, loses its immediate parent, or places another major section between `The Interdefinables` and `Preamble` in the controlling remote canon.
diff --git a/scripts/canon-parser.mjs b/scripts/canon-parser.mjs
index eb01343..c48e92d 100644
--- a/scripts/canon-parser.mjs
+++ b/scripts/canon-parser.mjs
@@ -5,10 +5,10 @@ import slugify from 'slugify';
 // id: canon_parser_core
 //   module_name: canon-parser
 //   module_kind: engine
-//   summary: Parses canonical or recovery text into stable sections, units, notes, routes, and provenance-bearing hashes.
+//   summary: Parses canonical or recovery text into stable sections, nested heading units, notes, routes, and provenance-bearing hashes.
 //   owner: Erin Spencer
 //   public_surface: parseCanon, detectHeading, extractNotes
-//   internal_surface: slug, boundedRouteSlug, parseDefinitionLine, extractNoteMarkers
+//   internal_surface: slug, boundedRouteSlug, canonicalHeadingLevel, parseDefinitionLine, extractNoteMarkers
 //   auth_boundary: none
 //   storage_boundary: none
 //   network_boundary: none
@@ -16,12 +16,12 @@ import slugify from 'slugify';
 //   admin_only: false
 //   tests: tests/canon-parser.test.mjs, tests/canon-integrity.test.mjs
 //   rollout: imported by scripts/parse-canon.mjs during every canon refresh
-//   rollback: restore the prior inline parser and remove this import
+//   rollback: restore the prior parser version and remove nested heading-parent edges
 // === END MODULE_BUILD ===
-// Usage: import parseCanon(text, provenance); run `node --test tests/canon-parser.test.mjs` for recovery and note fixtures.
-// Limits: heading recognition is canon-specific; unknown headings remain body text and must surface as hmmm during editorial review.
+// Usage: import parseCanon(text, provenance); run `node --test tests/canon-parser.test.mjs` for hierarchy, recovery, and note fixtures.
+// Limits: heading recognition is canon-specific; unknown headings retain normalized source levels and must surface as hmmm during editorial review.
 
-export const parserVersion = '0.5.0';
+export const parserVersion = '0.6.0';
 
 function slug(value) {
   return slugify(value, { lower: true, strict: true }) || 'unit';
@@ -34,39 +34,40 @@ function boundedRouteSlug(id) {
   return `${candidate.slice(0, 84).replace(/-+$/, '')}-${suffix}`;
 }
 
+function canonicalHeadingLevel(value) {
+  const title = value.trim().replace(/:\s*$/, '');
+  if (/^The Interdependent Way$/i.test(title)) return 1;
+  if (/^(Awakening|The Interdefinables|Preamble|Etiquette of the Body Politic)$/i.test(title)) return 2;
+  if (/^Rights.+of The Way[⁰¹²³⁴⁵⁶⁷⁸⁹]*$/i.test(title)) return 2;
+  if (/^Addendum:\s+.+$/i.test(value.trim())) return 2;
+  if (/^Human consciousness emerges from$/i.test(title)) return 3;
+  if (/^Article\s+(One|Two|Three|Four|Five|Six|Seven|Eight)(?:\s+\([^)]+\))?$/i.test(title)) return 3;
+  if (/^Binary essences meaningfully.*rooted[.]?$/i.test(title)) return 4;
+  if (/^Trinary perceptual focal (?:states|constructs) of complex system spirals/i.test(title)) return 4;
+  if (/^Trinary (?:states of social perception|social perception focal states)/i.test(title)) return 4;
+  if (/^(?:Five dominant )?Archetype passions of possession/i.test(title)) return 4;
+  if (/^(Summary|One-sentence takeaway \(exactly as previously given\))$/i.test(title)) return 3;
+  return null;
+}
+
 export function detectHeading(line) {
   const markdown = /^(#{1,6})\s+(.+?)\s*$/.exec(line);
   if (markdown) {
     const sourceLevel = markdown[1].length;
-    // The recovery mirror uses H3 for the same major divisions that the plain-text
-    // canon expresses as level 2, and H4 for article units. Normalize those levels
-    // before assigning parents so offline and remote builds have the same structure.
-    const level = sourceLevel >= 3 ? sourceLevel - 1 : sourceLevel;
-    return {
-      level,
-      sourceLevel,
-      title: markdown[2].replace(/#+$/, '').trim(),
-      syntax: 'markdown'
-    };
+    const title = markdown[2].replace(/#+$/, '').trim();
+    const declaredLevel = canonicalHeadingLevel(title);
+    // Recovery Markdown historically used H3 for both major sections and the
+    // Human-consciousness subheading. Canonical title semantics take priority;
+    // unknown headings retain the established H3→2 / H4→3 normalization.
+    const level = declaredLevel ?? (sourceLevel >= 3 ? sourceLevel - 1 : sourceLevel);
+    return { level, sourceLevel, title, syntax: 'markdown' };
   }
 
   const title = line.trim();
   if (!title) return null;
-  if (title === 'The Interdependent Way') return { level: 1, sourceLevel: 1, title, syntax: 'plain' };
-  if (/^(Awakening|The Interdefinables|Human consciousness emerges from|Preamble|Etiquette of the Body Politic)$/i.test(title)) {
-    return { level: 2, sourceLevel: 2, title, syntax: 'plain' };
-  }
-  if (/^Rights[\w\s’'&⁰¹²³⁴⁵⁶⁷⁸⁹-]+of The Way[⁰¹²³⁴⁵⁶⁷⁸⁹]*$/i.test(title)) {
-    return { level: 2, sourceLevel: 2, title, syntax: 'plain' };
-  }
-  if (/^Addendum:\s+.+$/i.test(title)) return { level: 2, sourceLevel: 2, title, syntax: 'plain' };
-  if (/^Article\s+(One|Two|Three|Four|Five|Six|Seven|Eight)(?:\s+\([^)]+\))?$/i.test(title)) {
-    return { level: 3, sourceLevel: 3, title, syntax: 'plain' };
-  }
-  if (/^(Binary essences meaningfully, divided; then, rooted\.|Trinary perceptual focal states of complex system spirals:.+|Trinary states of social perception:|Archetype passions of possession\..+|Summary|One-sentence takeaway \(exactly as previously given\))$/i.test(title)) {
-    return { level: 3, sourceLevel: 3, title, syntax: 'plain' };
-  }
-  return null;
+  const level = canonicalHeadingLevel(title);
+  if (!level) return null;
+  return { level, sourceLevel: level, title, syntax: 'plain' };
 }
 
 function parseDefinitionLine(line) {
@@ -111,6 +112,7 @@ export function parseCanon(text, provenance = {}) {
   const documentHash = createHash('sha256').update(text).digest('hex');
   const units = [];
   const sections = [];
+  const headingStack = [];
   let current = null;
   let sectionId = 'source';
 
@@ -140,16 +142,22 @@ export function parseCanon(text, provenance = {}) {
       }
     }
 
+    const parent = [...headingStack].reverse().find(entry => entry.level < level) ?? null;
+    const id = `${sectionId}.${slug(title)}`;
     current = {
-      id: `${sectionId}.${slug(title)}`,
+      id,
       title,
       section: sectionId,
+      parentId: parent?.id ?? null,
       level,
       sourceLevel,
       syntax,
       startLine: index + 1,
       lines: [lines[index]]
     };
+
+    while (headingStack.length && headingStack.at(-1).level >= level) headingStack.pop();
+    headingStack.push({ id, level });
   }
   finish(lines.length);
 
@@ -178,6 +186,9 @@ export function parseCanon(text, provenance = {}) {
     sections,
     units: units.map(({ lines: ignored, ...unit }) => unit),
     notes,
-    edges: units.map(unit => ({ from: unit.id, to: unit.section, type: 'unit-parent' }))
+    edges: [
+      ...units.map(unit => ({ from: unit.id, to: unit.section, type: 'unit-parent' })),
+      ...units.filter(unit => unit.parentId).map(unit => ({ from: unit.id, to: unit.parentId, type: 'heading-parent' }))
+    ]
   };
 }
diff --git a/scripts/validate-content.mjs b/scripts/validate-content.mjs
index 3b75702..fc796bd 100644
--- a/scripts/validate-content.mjs
+++ b/scripts/validate-content.mjs
@@ -5,18 +5,18 @@ import { access, readFile } from 'node:fs/promises';
 // id: generated_content_gate
 //   module_name: validate-content
 //   module_kind: instrument
-//   summary: Refuses deployment when canon identity, snapshot integrity, generated route coverage, or recovery artifacts drift.
+//   summary: Refuses deployment when canon identity, heading hierarchy, snapshot integrity, generated route coverage, or recovery artifacts drift.
 //   owner: Erin Spencer
 //   public_surface: npm run validate
-//   internal_surface: canon snapshot digest and repository-route assertions
+//   internal_surface: canon snapshot digest, heading hierarchy, and repository-route assertions
 //   auth_boundary: none
 //   storage_boundary: read
 //   network_boundary: none
 //   user_data_boundary: none
 //   admin_only: false
-//   tests: tests/canon-integrity.test.mjs, tests/repo-coverage.test.mjs, tests/site-contract.test.mjs
+//   tests: tests/canon-parser.test.mjs, tests/canon-integrity.test.mjs, tests/repo-coverage.test.mjs, tests/site-contract.test.mjs
 //   rollout: required by npm run build and npm run check
-//   rollback: remove the gate only with an explicit replacement preserving provenance and route checks
+//   rollback: remove the gate only with an explicit replacement preserving provenance, hierarchy, and route checks
 // === END MODULE_BUILD ===
 // Usage: run `npm run validate`; it refreshes data first and exits nonzero on any integrity mismatch.
 // Limits: validates repository artifacts, not GitHub Pages settings or public DNS.
@@ -47,8 +47,26 @@ if (!canon.source.contentSha256 || canon.source.contentSha256.length !== 64) thr
 if (canon.source.contentSha256 !== snapshotHash) throw new Error('generated canon digest does not match selected snapshot');
 if (!canon.source.fallback && (!canon.source.commit || !canon.source.blob)) throw new Error('remote canon provenance missing commit or blob SHA');
 if (!canon.units.length || canon.units.some(unit => !unit.hash || !unit.id)) throw new Error('canon units missing identity or hash');
+
+const interdefinables = canon.units.find(unit => unit.title === 'The Interdefinables');
+const humanConsciousness = canon.units.find(unit => /^Human consciousness emerges from:?$/i.test(unit.title));
+const preamble = canon.units.find(unit => unit.title === 'Preamble');
+if (!interdefinables || !humanConsciousness || !preamble) throw new Error('canon missing Interdefinables, Human consciousness, or Preamble hierarchy unit');
+if (humanConsciousness.level !== 3) throw new Error('Human consciousness emerges from must be a level-3 subheading');
+if (humanConsciousness.section !== interdefinables.section) throw new Error('Human consciousness emerges from escaped The Interdefinables section');
+if (humanConsciousness.parentId !== interdefinables.id) throw new Error('Human consciousness emerges from must be parented by The Interdefinables');
+if (canon.sections.some(section => /^Human consciousness emerges from:?$/i.test(section.title))) throw new Error('Human consciousness emerges from must not be promoted to a peer section');
+if (preamble.level !== 2 || preamble.section !== 'preamble') throw new Error('Preamble must remain the next major section boundary');
+if (!canon.source.fallback) {
+  const interdefinablesIndex = canon.sections.findIndex(section => section.title === 'The Interdefinables');
+  const preambleIndex = canon.sections.findIndex(section => section.title === 'Preamble');
+  if (interdefinablesIndex < 0 || preambleIndex !== interdefinablesIndex + 1) {
+    throw new Error('Preamble must be the next major section after The Interdefinables');
+  }
+}
+
 if (repos.publicRepoCount !== repos.generatedRouteCount) throw new Error('repo route mismatch');
 if (new Set(repos.repositories.map(repo => repo.slug)).size !== repos.repositories.length) throw new Error('duplicate project slug');
 await access('fallback/index.html');
 await access('artifacts/four-cuts-1.html');
-console.log(`validated ${canon.units.length} canon units, ${canon.notes.length} notes, and ${repos.publicRepoCount} repositories`);
+console.log(`validated ${canon.units.length} canon units, ${canon.notes.length} notes, canonical heading hierarchy, and ${repos.publicRepoCount} repositories`);
diff --git a/src/assets/css/site.css b/src/assets/css/site.css
index 9adc07a..58b52ac 100644
--- a/src/assets/css/site.css
+++ b/src/assets/css/site.css
@@ -80,6 +80,10 @@ h3 { font-size: clamp(1.2rem, 2vw, 1.55rem); }
 .index-list a { display: grid; grid-template-columns: 7rem 1fr auto; gap: 1rem; align-items: baseline; padding: .9rem 1rem; border: 1px solid var(--line); border-radius: .75rem; background: rgba(16,24,42,.75); color: inherit; text-decoration: none; }
 .index-list a:hover { border-color: var(--violet); }
 .index-list small { color: var(--silver); }
+.canon-outline .unit-level-3 { margin-left: clamp(1rem, 3vw, 2.5rem); }
+.canon-outline .unit-level-4 { margin-left: clamp(2rem, 6vw, 5rem); }
+.canon-outline .unit-level-3 a { border-left: .25rem solid var(--violet); }
+.canon-outline .unit-level-4 a { border-left: .25rem solid var(--cyan); background: rgba(9, 13, 24, .76); }
 .source-block { white-space: pre-wrap; overflow-wrap: anywhere; padding: 1rem; border: 1px solid var(--line); border-radius: .8rem; background: #070a12; color: #dce6fa; font: .92rem/1.6 ui-monospace, SFMono-Regular, Consolas, monospace; }
 dl.meta { display: grid; grid-template-columns: minmax(9rem, .35fr) 1fr; gap: .45rem 1rem; }
 dl.meta dt { color: var(--silver); }
@@ -104,6 +108,8 @@ summary { cursor: pointer; font-weight: 800; }
   .hero { grid-template-columns: 1fr; min-height: auto; }
   .hero-field { max-width: 22rem; width: 78%; margin: 1rem auto; }
   .index-list a { grid-template-columns: 1fr; gap: .15rem; }
+  .canon-outline .unit-level-3 { margin-left: .65rem; }
+  .canon-outline .unit-level-4 { margin-left: 1.3rem; }
   .site-footer { grid-template-columns: 1fr; }
   .hmmm-boundary { grid-column: auto; grid-template-columns: 1fr; }
 }
diff --git a/src/way/index.njk b/src/way/index.njk
index 720c52d..69198e1 100644
--- a/src/way/index.njk
+++ b/src/way/index.njk
@@ -1,9 +1,9 @@
 ---
 layout: layouts/base.njk
 title: Explore The Way
-description: A sectioned companion map of The Interdependent Way, with exact source available one deliberate layer deeper.
+description: A sectioned and nested companion map of The Interdependent Way, with exact source available one deliberate layer deeper.
 ---
-<header class="page-head"><p class="eyebrow">Canon-derived map</p><h1>Explore The Way</h1><p class="lede">This layer identifies the shape and relations of the source. It does not replace the canon. Open a unit for orientation, then choose its Lab conversation or exact source.</p></header>
+<header class="page-head"><p class="eyebrow">Canon-derived map</p><h1>Explore The Way</h1><p class="lede">This layer identifies the shape and relations of the source. Major sections, subheadings, and nested headings remain visibly distinct. It does not replace the canon. Open a unit for orientation, then choose its Lab conversation or exact source.</p></header>
 {% for section in generated.canon.sections %}
-<section class="category"><p class="eyebrow">{{ section.id }}</p><h2>{{ section.title }}</h2><ul class="index-list">{% for unit in generated.canon.units %}{% if unit.section == section.id %}<li><a href="/way/{{ unit.routeSlug }}/"><small>lines {{ unit.startLine }}–{{ unit.endLine }}</small><strong>{{ unit.title }}</strong><span class="status status-canon">canon-derived</span></a></li>{% endif %}{% endfor %}</ul></section>
+<section class="category"><p class="eyebrow">{{ section.id }}</p><h2>{{ section.title }}</h2><ul class="index-list canon-outline">{% for unit in generated.canon.units %}{% if unit.section == section.id %}<li class="unit-level-{{ unit.level }}" data-parent-id="{{ unit.parentId or '' }}"><a href="/way/{{ unit.routeSlug }}/"><small>lines {{ unit.startLine }}–{{ unit.endLine }} · {% if unit.level <= 2 %}section{% elif unit.level == 3 %}subheading{% else %}nested heading{% endif %}</small><strong>{{ unit.title }}</strong><span class="status status-canon">canon-derived</span></a></li>{% endif %}{% endfor %}</ul></section>
 {% endfor %}
diff --git a/src/way/unit.njk b/src/way/unit.njk
index 12fef2b..1f62733 100644
--- a/src/way/unit.njk
+++ b/src/way/unit.njk
@@ -7,8 +7,8 @@ pagination:
 permalink: "/way/{{ unit.routeSlug }}/"
 title: "{{ unit.title }}"
 ---
-<nav class="breadcrumb" aria-label="Breadcrumb"><a href="/">Home</a> / <a href="/way/">The Way</a> / {{ unit.title }}</nav>
+<nav class="breadcrumb" aria-label="Breadcrumb"><a href="/home/">Home</a> / <a href="/way/">The Way</a> / {{ unit.title }}</nav>
 <header class="page-head"><p class="eyebrow">Canon-derived companion · {{ unit.section }}</p><h1>{{ unit.title }}</h1><div class="status-row"><span class="status status-canon">canon-derived</span><span class="status status-interpretation">orientation pending review</span></div><p class="lede">This page preserves the unit’s identity and location while offering paths into interpretation and exact source. It does not rewrite the canonical text.</p></header>
-<section class="panel"><h2>Place in the document</h2><dl class="meta"><dt>Unit ID</dt><dd><code>{{ unit.id }}</code></dd><dt>Stable route</dt><dd><code>{{ unit.routeSlug }}</code></dd><dt>Source lines</dt><dd>{{ unit.startLine }}–{{ unit.endLine }}</dd><dt>Detected notes</dt><dd>{{ unit.notes.length }}</dd><dt>Unit digest</dt><dd><code>{{ unit.hash }}</code></dd></dl></section>
+<section class="panel"><h2>Place in the document</h2><dl class="meta"><dt>Unit ID</dt><dd><code>{{ unit.id }}</code></dd><dt>Heading level</dt><dd>{{ unit.level }}</dd>{% if unit.parentId %}<dt>Parent heading</dt><dd>{% for parent in generated.canon.units %}{% if parent.id == unit.parentId %}<a href="/way/{{ parent.routeSlug }}/">{{ parent.title }}</a>{% endif %}{% endfor %}</dd>{% endif %}<dt>Stable route</dt><dd><code>{{ unit.routeSlug }}</code></dd><dt>Source lines</dt><dd>{{ unit.startLine }}–{{ unit.endLine }}</dd><dt>Detected notes</dt><dd>{{ unit.notes.length }}</dd><dt>Unit digest</dt><dd><code>{{ unit.hash }}</code></dd></dl></section>
 <section class="hmmm"><h2>Companion reading</h2><p>A reviewed plain-language reading has not yet been admitted for this unit. The source operators, conditions, exceptions, and obligations must remain intact before this field is populated.</p></section>
 <div class="actions"><a class="button" href="/lab/{{ unit.routeSlug }}/">Enter this unit’s Lab</a><a class="button secondary" href="/source/{{ unit.routeSlug }}/">Read exact source</a></div>
diff --git a/tests/canon-integrity.test.mjs b/tests/canon-integrity.test.mjs
index 3165fa3..4ceaa8d 100644
--- a/tests/canon-integrity.test.mjs
+++ b/tests/canon-integrity.test.mjs
@@ -2,7 +2,7 @@ import test from 'node:test';
 import assert from 'node:assert/strict';
 import { readFile } from 'node:fs/promises';
 
-test('canon data preserves Wayseer identity, provenance, and stable unit evidence', async () => {
+test('canon data preserves Wayseer identity, provenance, stable unit evidence, and nested heading parents', async () => {
   const canon = JSON.parse(await readFile('src/_data/generated/canon.json', 'utf8'));
   assert.equal(canon.source.repository, 'wayseer00/main');
   assert.equal(canon.source.path, 'canon/INTERDEPENDENT_WAY.txt');
@@ -23,4 +23,14 @@ test('canon data preserves Wayseer identity, provenance, and stable unit evidenc
     assert.equal(routes.has(unit.routeSlug), false);
     routes.add(unit.routeSlug);
   }
+
+  const interdefinables = canon.units.find(unit => unit.title === 'The Interdefinables');
+  const human = canon.units.find(unit => /^Human consciousness emerges from:?$/i.test(unit.title));
+  assert.ok(interdefinables);
+  assert.ok(human);
+  assert.equal(human.level, 3);
+  assert.equal(human.section, interdefinables.section);
+  assert.equal(human.parentId, interdefinables.id);
+  assert.equal(canon.sections.some(section => /^Human consciousness emerges from:?$/i.test(section.title)), false);
+  assert.ok(canon.edges.some(edge => edge.type === 'heading-parent' && edge.from === human.id && edge.to === interdefinables.id));
 });
diff --git a/tests/canon-parser.test.mjs b/tests/canon-parser.test.mjs
index 46c9254..ad03589 100644
--- a/tests/canon-parser.test.mjs
+++ b/tests/canon-parser.test.mjs
@@ -14,6 +14,49 @@ test('Markdown recovery headings normalize to plain-canon parent levels', () =>
   assert.ok(data.sections.some(section => section.id === 'rights-and-definitions-of-the-way' && section.level === 2));
 });
 
+test('Interdefinables owns the Human consciousness hierarchy until Preamble', () => {
+  const data = parseCanon(`The Interdependent Way\n\nAwakening\nOpening.\n\nThe Interdefinables\nDefinitions.\n\nHuman consciousness emerges from\nBinary essences meaningfully, divided; then, rooted.\nBody.\nTrinary perceptual focal states of complex system spirals: mind (body) soul\nBody.\nPreamble\nCivic claim.`);
+  const interdefinables = data.units.find(unit => unit.title === 'The Interdefinables');
+  const human = data.units.find(unit => unit.title === 'Human consciousness emerges from');
+  const binary = data.units.find(unit => unit.title.startsWith('Binary essences'));
+  const trinary = data.units.find(unit => unit.title.startsWith('Trinary perceptual'));
+  const preamble = data.units.find(unit => unit.title === 'Preamble');
+
+  assert.equal(interdefinables.level, 2);
+  assert.equal(human.level, 3);
+  assert.equal(human.section, 'interdefinables');
+  assert.equal(human.parentId, interdefinables.id);
+  assert.equal(binary.level, 4);
+  assert.equal(binary.section, 'interdefinables');
+  assert.equal(binary.parentId, human.id);
+  assert.equal(trinary.level, 4);
+  assert.equal(trinary.parentId, human.id);
+  assert.equal(preamble.level, 2);
+  assert.equal(preamble.section, 'preamble');
+  assert.equal(data.sections.some(section => /^Human consciousness/.test(section.title)), false);
+  assert.ok(data.sections.findIndex(section => section.title === 'The Interdefinables') < data.sections.findIndex(section => section.title === 'Preamble'));
+  assert.ok(data.edges.some(edge => edge.type === 'heading-parent' && edge.from === human.id && edge.to === interdefinables.id));
+});
+
+test('legacy Markdown title levels cannot promote Human consciousness to a peer section', () => {
+  const data = parseCanon(`# The Interdependent Way\n### The Interdefinables\nDefinitions.\n### Human consciousness emerges from:\n#### Binary essences meaningfully divided, then rooted:\nBody.\n### Preamble\nCivic claim.`);
+  const interdefinables = data.units.find(unit => unit.title === 'The Interdefinables');
+  const human = data.units.find(unit => /^Human consciousness/.test(unit.title));
+  const binary = data.units.find(unit => unit.title.startsWith('Binary essences'));
+  const preamble = data.units.find(unit => unit.title === 'Preamble');
+
+  assert.equal(human.sourceLevel, 3);
+  assert.equal(human.level, 3);
+  assert.equal(human.section, 'interdefinables');
+  assert.equal(human.parentId, interdefinables.id);
+  assert.equal(binary.sourceLevel, 4);
+  assert.equal(binary.level, 4);
+  assert.equal(binary.parentId, human.id);
+  assert.equal(preamble.sourceLevel, 3);
+  assert.equal(preamble.level, 2);
+  assert.equal(preamble.section, 'preamble');
+});
+
 test('multiple superscript note definitions on one physical line remain distinct', () => {
   assert.deepEqual(extractNotes('>¹ first tension ² second tension ³ third tension'), [
     { marker: '¹', text: 'first tension' },
diff --git a/tests/generated-site.test.mjs b/tests/generated-site.test.mjs
index 29a67f3..7aef9f0 100644
--- a/tests/generated-site.test.mjs
+++ b/tests/generated-site.test.mjs
@@ -46,6 +46,22 @@ test('generated deployment artifact contains the unified routes', async () => {
   ]) assert.match(articles, new RegExp(title.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')));
 });
 
+test('Way map renders Human consciousness beneath Interdefinables and before Preamble', async () => {
+  const way = await readFile('_site/way/index.html', 'utf8');
+  const interdefinablesSection = way.indexOf('<h2>The Interdefinables</h2>');
+  const humanHeading = way.indexOf('Human consciousness emerges from');
+  const binaryHeading = way.indexOf('Binary essences meaningfully');
+  const preambleSection = way.indexOf('<h2>Preamble</h2>');
+
+  assert.ok(interdefinablesSection >= 0, 'Interdefinables section missing');
+  assert.ok(humanHeading > interdefinablesSection, 'Human consciousness must appear inside Interdefinables');
+  assert.ok(binaryHeading > humanHeading, 'Human consciousness child headings must follow their parent');
+  assert.ok(preambleSection > binaryHeading, 'Preamble must be the next major section after Interdefinables');
+  assert.match(way, /class="unit-level-3"[^>]*>[\s\S]*?Human consciousness emerges from/);
+  assert.match(way, /class="unit-level-4"[^>]*>[\s\S]*?Binary essences meaningfully/);
+  assert.doesNotMatch(way, /<h2>Human consciousness emerges from:?<\/h2>/);
+});
+
 test('generated deployment artifact contains all rights article vertical slices', async () => {
   const pages = [
     ['article-one', /Contribution without contempt/, /From each as they will/],