diff --git a/content/public/asset-manifest.json b/content/public/asset-manifest.json
index ae9a757..cd4bf11 100644
--- a/content/public/asset-manifest.json
+++ b/content/public/asset-manifest.json
@@ -47,6 +47,54 @@
       "rightsHolder": "Luca Pîslaru",
       "license": "All rights reserved",
       "attribution": "Original AI-assisted soundtrack produced by Luca Pîslaru with ACE-Step 1.5"
+    },
+    {
+      "id": "soundtrack-afterglow-opus",
+      "fileName": "nightdrive-afterglow.opus",
+      "sha256": "693215397e8ae4c2c13a4a6e4cc74b0059fb26b396c7f35d99e0e2c3e738d4b1",
+      "mediaType": "audio/ogg",
+      "width": null,
+      "height": null,
+      "durationMs": 25123,
+      "rightsHolder": "Luca Pîslaru",
+      "license": "All rights reserved",
+      "attribution": "Original AI-assisted soundtrack produced by Luca Pîslaru with ACE-Step 1.5"
+    },
+    {
+      "id": "soundtrack-afterglow-mp3",
+      "fileName": "nightdrive-afterglow.mp3",
+      "sha256": "685687ad131d61c34e42bcee29af16a4c8180d788c67d75f2331fa9082a3a44e",
+      "mediaType": "audio/mpeg",
+      "width": null,
+      "height": null,
+      "durationMs": 25116,
+      "rightsHolder": "Luca Pîslaru",
+      "license": "All rights reserved",
+      "attribution": "Original AI-assisted soundtrack produced by Luca Pîslaru with ACE-Step 1.5"
+    },
+    {
+      "id": "soundtrack-drive-lift-opus",
+      "fileName": "nightdrive-drive-lift.opus",
+      "sha256": "d580e58039c9d700599cf100c96b50d4b5816d93a0af738a93a1e8646fbb7566",
+      "mediaType": "audio/ogg",
+      "width": null,
+      "height": null,
+      "durationMs": 11169,
+      "rightsHolder": "Luca Pîslaru",
+      "license": "All rights reserved",
+      "attribution": "Original AI-assisted soundtrack produced by Luca Pîslaru with ACE-Step 1.5"
+    },
+    {
+      "id": "soundtrack-drive-lift-mp3",
+      "fileName": "nightdrive-drive-lift.mp3",
+      "sha256": "edcb802938d3d1e53392f9ccd2e153f72a24b494c205ce6f556d73de5fe709ec",
+      "mediaType": "audio/mpeg",
+      "width": null,
+      "height": null,
+      "durationMs": 11163,
+      "rightsHolder": "Luca Pîslaru",
+      "license": "All rights reserved",
+      "attribution": "Original AI-assisted soundtrack produced by Luca Pîslaru with ACE-Step 1.5"
     }
   ]
 }
diff --git a/content/public/portfolio-content.json b/content/public/portfolio-content.json
index 1405688..d85b725 100644
--- a/content/public/portfolio-content.json
+++ b/content/public/portfolio-content.json
@@ -253,6 +253,14 @@
     "main": {
       "opusAssetId": "soundtrack-main-opus",
       "mp3AssetId": "soundtrack-main-mp3"
+    },
+    "afterglow": {
+      "opusAssetId": "soundtrack-afterglow-opus",
+      "mp3AssetId": "soundtrack-afterglow-mp3"
+    },
+    "driveLift": {
+      "opusAssetId": "soundtrack-drive-lift-opus",
+      "mp3AssetId": "soundtrack-drive-lift-mp3"
     }
   },
   "sceneDescription": "A restrained retro-futuristic night drive supports the reading journey while the portfolio content remains fully available as a semantic document."
diff --git a/inputs/prepared-assets/nightdrive-afterglow.mp3 b/inputs/prepared-assets/nightdrive-afterglow.mp3
new file mode 100644
index 0000000..342cd20
Binary files /dev/null and b/inputs/prepared-assets/nightdrive-afterglow.mp3 differ
diff --git a/inputs/prepared-assets/nightdrive-afterglow.opus b/inputs/prepared-assets/nightdrive-afterglow.opus
new file mode 100644
index 0000000..e20cffc
Binary files /dev/null and b/inputs/prepared-assets/nightdrive-afterglow.opus differ
diff --git a/inputs/prepared-assets/nightdrive-drive-lift.mp3 b/inputs/prepared-assets/nightdrive-drive-lift.mp3
new file mode 100644
index 0000000..dcf8598
Binary files /dev/null and b/inputs/prepared-assets/nightdrive-drive-lift.mp3 differ
diff --git a/inputs/prepared-assets/nightdrive-drive-lift.opus b/inputs/prepared-assets/nightdrive-drive-lift.opus
new file mode 100644
index 0000000..a13bb7a
Binary files /dev/null and b/inputs/prepared-assets/nightdrive-drive-lift.opus differ
diff --git a/scripts/check-bundle-budgets.mjs b/scripts/check-bundle-budgets.mjs
index 1a5b5e5..8d9be79 100644
--- a/scripts/check-bundle-budgets.mjs
+++ b/scripts/check-bundle-budgets.mjs
@@ -76,7 +76,12 @@ for (const group of content.toolkit ?? []) for (const technology of group.techno
 }
 if (content.metadata?.socialPreviewAssetId) assetClassById.set(content.metadata.socialPreviewAssetId, 'project-still');
 if (content.soundtrack) {
-  for (const region of [content.soundtrack.intro, content.soundtrack.main]) {
+  for (const region of [
+    content.soundtrack.intro,
+    content.soundtrack.main,
+    content.soundtrack.afterglow,
+    content.soundtrack.driveLift,
+  ]) {
     if (region?.opusAssetId) assetClassById.set(region.opusAssetId, 'soundtrack-audio');
     if (region?.mp3AssetId) assetClassById.set(region.mp3AssetId, 'soundtrack-audio');
   }
diff --git a/scripts/lib/bundle-budgets.mjs b/scripts/lib/bundle-budgets.mjs
index 662d0fa..a600d8e 100644
--- a/scripts/lib/bundle-budgets.mjs
+++ b/scripts/lib/bundle-budgets.mjs
@@ -13,7 +13,7 @@ export const PERFORMANCE_BUDGETS = Object.freeze({
   deferredProjectVisuals: 2.5 * 1024 * 1024,
   highTierExtras: 750 * 1024,
   deferredNonVideo: 3.5 * 1024 * 1024,
-  deferredAudio: 13 * 1024 * 1024,
+  deferredAudio: 16 * 1024 * 1024,
   imageSceneConcurrency: 2,
   videoConcurrency: 1,
   mobileTextureDimension: 2048,
@@ -44,7 +44,7 @@ export const classifyArtifact = (path, source = '') => {
   if (/^assets\/project-[^/]+\.(?:webm|mp4)$/u.test(path)) return 'project-video';
   if (/^assets\/project-[^/]*chart[^/]*\.(?:avif|webp|png|jpe?g)$/u.test(path)) return 'chart';
   if (/^assets\/project-[^/]+\.(?:avif|webp|png|jpe?g|svg)$/u.test(path)) return 'project-still';
-  if (/^assets\/nightdrive-(?:intro|main)\.(?:opus|mp3)$/u.test(path)) return 'soundtrack-audio';
+  if (/^assets\/nightdrive-(?:intro|main|afterglow|drive-lift)\.(?:opus|mp3)$/u.test(path)) return 'soundtrack-audio';
   if (/^(?:robots\.txt|sitemap\.xml|_headers\.example|_redirects\.example)$/u.test(path)) return 'release-metadata';
   throw new Error(`Artifact is unclassified: ${path}`);
 };
diff --git a/scripts/materialize-empty-asset-set.mjs b/scripts/materialize-empty-asset-set.mjs
index dd2208b..9cedb60 100644
--- a/scripts/materialize-empty-asset-set.mjs
+++ b/scripts/materialize-empty-asset-set.mjs
@@ -132,7 +132,7 @@ const assetReferences = (content) => {
     if (typeof content.soundtrack !== 'object' || content.soundtrack === null || Array.isArray(content.soundtrack)) {
       throw new Error('Portfolio soundtrack must be an object.');
     }
-    for (const regionName of ['intro', 'main']) {
+    for (const regionName of ['intro', 'main', 'afterglow', 'driveLift']) {
       const region = content.soundtrack[regionName];
       if (typeof region !== 'object' || region === null || Array.isArray(region)) {
         throw new Error(`Portfolio soundtrack ${regionName} must be an object.`);
diff --git a/src/content/schemas.ts b/src/content/schemas.ts
index ff09b30..04dff9b 100644
--- a/src/content/schemas.ts
+++ b/src/content/schemas.ts
@@ -202,6 +202,8 @@ const portfolioContentSchema = z.object({
   soundtrack: z.object({
     intro: soundtrackAssetSourcesSchema,
     main: soundtrackAssetSourcesSchema,
+    afterglow: soundtrackAssetSourcesSchema,
+    driveLift: soundtrackAssetSourcesSchema,
   }).strict().optional(),
   sceneDescription: visibleString,
 }).strict().superRefine((content, context) => {
@@ -321,6 +323,10 @@ export const parseProductionInputSnapshot = (input: unknown): ProductionInputs =
       content.soundtrack.intro.mp3AssetId,
       content.soundtrack.main.opusAssetId,
       content.soundtrack.main.mp3AssetId,
+      content.soundtrack.afterglow.opusAssetId,
+      content.soundtrack.afterglow.mp3AssetId,
+      content.soundtrack.driveLift.opusAssetId,
+      content.soundtrack.driveLift.mp3AssetId,
     ]),
   ];
   const seenReferences = new Set<string>();
diff --git a/src/content/types.ts b/src/content/types.ts
index a83809a..144cc3c 100644
--- a/src/content/types.ts
+++ b/src/content/types.ts
@@ -141,6 +141,8 @@ export interface SoundtrackAssetSources {
 export interface SoundtrackContent {
   intro: SoundtrackAssetSources;
   main: SoundtrackAssetSources;
+  afterglow: SoundtrackAssetSources;
+  driveLift: SoundtrackAssetSources;
 }
 
 export interface PortfolioContent {
diff --git a/tests/integration/materialize-empty-asset-set.test.mjs b/tests/integration/materialize-empty-asset-set.test.mjs
index 82b574a..7002dd1 100644
--- a/tests/integration/materialize-empty-asset-set.test.mjs
+++ b/tests/integration/materialize-empty-asset-set.test.mjs
@@ -64,6 +64,10 @@ describe('approved asset publication closure', () => {
       ['soundtrack-intro-mp3', 'nightdrive-intro.mp3'],
       ['soundtrack-main-opus', 'nightdrive-main.opus'],
       ['soundtrack-main-mp3', 'nightdrive-main.mp3'],
+      ['soundtrack-afterglow-opus', 'nightdrive-afterglow.opus'],
+      ['soundtrack-afterglow-mp3', 'nightdrive-afterglow.mp3'],
+      ['soundtrack-drive-lift-opus', 'nightdrive-drive-lift.opus'],
+      ['soundtrack-drive-lift-mp3', 'nightdrive-drive-lift.mp3'],
     ].map(([id, fileName], index) => {
       const bytes = Buffer.from(`approved soundtrack asset ${index}`);
       return { id, fileName, bytes, sha256: createHash('sha256').update(bytes).digest('hex') };
@@ -78,6 +82,8 @@ describe('approved asset publication closure', () => {
       soundtrack: {
         intro: { opusAssetId: 'soundtrack-intro-opus', mp3AssetId: 'soundtrack-intro-mp3' },
         main: { opusAssetId: 'soundtrack-main-opus', mp3AssetId: 'soundtrack-main-mp3' },
+        afterglow: { opusAssetId: 'soundtrack-afterglow-opus', mp3AssetId: 'soundtrack-afterglow-mp3' },
+        driveLift: { opusAssetId: 'soundtrack-drive-lift-opus', mp3AssetId: 'soundtrack-drive-lift-mp3' },
       },
     }));
     await mkdir(join(root, 'inputs/prepared-assets'), { recursive: true });
diff --git a/tests/integration/public-content.test.ts b/tests/integration/public-content.test.ts
index 28e7ea0..2bec1a3 100644
--- a/tests/integration/public-content.test.ts
+++ b/tests/integration/public-content.test.ts
@@ -47,6 +47,10 @@ describe('approved public portfolio projection', () => {
         content.soundtrack.intro.mp3AssetId,
         content.soundtrack.main.opusAssetId,
         content.soundtrack.main.mp3AssetId,
+        content.soundtrack.afterglow.opusAssetId,
+        content.soundtrack.afterglow.mp3AssetId,
+        content.soundtrack.driveLift.opusAssetId,
+        content.soundtrack.driveLift.mp3AssetId,
       ]),
     ];
     expect([...publishedReferences].sort()).toEqual(manifest.assets.map((asset) => asset.id).sort());
diff --git a/tests/integration/verify-artifacts.test.ts b/tests/integration/verify-artifacts.test.ts
index a95a21f..0912114 100644
--- a/tests/integration/verify-artifacts.test.ts
+++ b/tests/integration/verify-artifacts.test.ts
@@ -118,6 +118,28 @@ describe('artifact verification', () => {
     await expect(verifyArtifactDirectory(directory, inputs, contract)).resolves.toBeUndefined();
   });
 
+  it.each([
+    {
+      name: 'an omitted adaptive soundtrack file',
+      mutate: async (directory: string) => rm(join(directory, 'assets/nightdrive-afterglow.opus')),
+      error: /missing.*artifact|digest|public asset/iu,
+    },
+    {
+      name: 'an altered adaptive soundtrack file',
+      mutate: async (directory: string) => writeFile(join(directory, 'assets/nightdrive-drive-lift.mp3'), 'altered'),
+      error: /digest does not match|hash/u,
+    },
+    {
+      name: 'an unreferenced adaptive soundtrack file',
+      mutate: async (directory: string) => writeFile(join(directory, 'assets/nightdrive-unreferenced.opus'), 'unreferenced'),
+      error: /unexpected artifact|unreferenced/u,
+    },
+  ])('rejects $name', async ({ mutate, error }) => {
+    const { directory, inputs, contract } = await writeValidArtifacts();
+    await mutate(directory);
+    await expect(verifyArtifactDirectory(directory, inputs, contract)).rejects.toThrow(error);
+  });
+
   it.each([
     {
       name: 'an unexpected preview sitemap',
diff --git a/tests/performance/budgets.test.ts b/tests/performance/budgets.test.ts
index 176c5f9..b0afb81 100644
--- a/tests/performance/budgets.test.ts
+++ b/tests/performance/budgets.test.ts
@@ -31,6 +31,7 @@ describe('release budgets', () => {
   });
 
   it('pins every exact section 14 threshold', () => {
+    expect(PERFORMANCE_BUDGETS.deferredAudio).toBe(16 * 1024 * 1024);
     expect(PERFORMANCE_BUDGETS).toMatchObject({
       initialHtmlCriticalCss: 100 * 1024,
       initialApplicationJs: 120 * 1024,
@@ -46,7 +47,7 @@ describe('release budgets', () => {
       deferredProjectVisuals: 2.5 * 1024 * 1024,
       highTierExtras: 750 * 1024,
       deferredNonVideo: 3.5 * 1024 * 1024,
-      deferredAudio: 13 * 1024 * 1024,
+      deferredAudio: 16 * 1024 * 1024,
       imageSceneConcurrency: 2,
       videoConcurrency: 1,
       mobileTextureDimension: 2048,
@@ -63,6 +64,10 @@ describe('release budgets', () => {
     expect(classifyArtifact('assets/nightdrive-grand-tourer-a.glb', '')).toBe('first-live-scene');
     expect(classifyArtifact('assets/nightdrive-main.opus', '')).toBe('soundtrack-audio');
     expect(classifyArtifact('assets/nightdrive-intro.mp3', '')).toBe('soundtrack-audio');
+    expect(classifyArtifact('assets/nightdrive-afterglow.opus', '')).toBe('soundtrack-audio');
+    expect(classifyArtifact('assets/nightdrive-afterglow.mp3', '')).toBe('soundtrack-audio');
+    expect(classifyArtifact('assets/nightdrive-drive-lift.opus', '')).toBe('soundtrack-audio');
+    expect(classifyArtifact('assets/nightdrive-drive-lift.mp3', '')).toBe('soundtrack-audio');
     expect(classifyArtifact('assets/high-tier-b.js', 'optional bloom')).toBe('high-tier-extras');
     expect(() => classifyArtifact('assets/mystery.bin', '')).toThrow(/unclassified/u);
   });
diff --git a/tests/unit/content-schemas.test.ts b/tests/unit/content-schemas.test.ts
index 7388afe..9b6af50 100644
--- a/tests/unit/content-schemas.test.ts
+++ b/tests/unit/content-schemas.test.ts
@@ -27,6 +27,8 @@ type MutableContentFixture = {
   soundtrack?: {
     intro: { opusAssetId: string; mp3AssetId: string };
     main: { opusAssetId: string; mp3AssetId: string };
+    afterglow: { opusAssetId: string; mp3AssetId: string };
+    driveLift: { opusAssetId: string; mp3AssetId: string };
   };
 };
 
@@ -48,6 +50,8 @@ describe('content schemas', () => {
     content.soundtrack = {
       intro: { opusAssetId: 'soundtrack-intro-opus', mp3AssetId: 'soundtrack-intro-mp3' },
       main: { opusAssetId: 'soundtrack-main-opus', mp3AssetId: 'soundtrack-main-mp3' },
+      afterglow: { opusAssetId: 'soundtrack-afterglow-opus', mp3AssetId: 'soundtrack-afterglow-mp3' },
+      driveLift: { opusAssetId: 'soundtrack-drive-lift-opus', mp3AssetId: 'soundtrack-drive-lift-mp3' },
     };
     const audioMetadata = {
       width: null,
@@ -61,6 +65,10 @@ describe('content schemas', () => {
       { id: 'soundtrack-intro-mp3', fileName: 'nightdrive-intro.mp3', sha256: 'b'.repeat(64), mediaType: 'audio/mpeg', durationMs: 56_064, ...audioMetadata },
       { id: 'soundtrack-main-opus', fileName: 'nightdrive-main.opus', sha256: 'c'.repeat(64), mediaType: 'audio/ogg', durationMs: 178_605, ...audioMetadata },
       { id: 'soundtrack-main-mp3', fileName: 'nightdrive-main.mp3', sha256: 'd'.repeat(64), mediaType: 'audio/mpeg', durationMs: 178_605, ...audioMetadata },
+      { id: 'soundtrack-afterglow-opus', fileName: 'nightdrive-afterglow.opus', sha256: 'e'.repeat(64), mediaType: 'audio/ogg', durationMs: 56_064, ...audioMetadata },
+      { id: 'soundtrack-afterglow-mp3', fileName: 'nightdrive-afterglow.mp3', sha256: 'f'.repeat(64), mediaType: 'audio/mpeg', durationMs: 56_064, ...audioMetadata },
+      { id: 'soundtrack-drive-lift-opus', fileName: 'nightdrive-drive-lift.opus', sha256: '1'.repeat(64), mediaType: 'audio/ogg', durationMs: 178_605, ...audioMetadata },
+      { id: 'soundtrack-drive-lift-mp3', fileName: 'nightdrive-drive-lift.mp3', sha256: '2'.repeat(64), mediaType: 'audio/mpeg', durationMs: 178_605, ...audioMetadata },
     ];
     const manifest = {
       assets: [...(validManifest as { assets: unknown[] }).assets, ...soundtrackAssets],