diff --git a/src/servers/api/plugins/router.ts b/src/servers/api/plugins/router.ts
index 950a01cb..261304db 100644
--- a/src/servers/api/plugins/router.ts
+++ b/src/servers/api/plugins/router.ts
@@ -4,7 +4,7 @@ import { isSuperAdmin } from '../../super-admin';
 import { mountPrefix } from '../../plugins/manifest';
 import { snapshotPlugins } from '../../plugins/mount';
 import { manualInstallHint, reportDependencies } from '../../plugins/os-deps';
-import { fetchCatalogue } from '../../plugins/marketplace';
+import { fetchCatalogue, fetchReadme } from '../../plugins/marketplace';
 import { iconUrl } from '../../app-store/assets';
 import {
   installPlugin,
@@ -40,6 +40,17 @@ pluginsRouter.use(async (ctx, next) => {
  * show the owner, and refusing the whole list because one plugin is malformed would hide the nine that
  * are fine.
  */
+// GET /plugins/catalogue/:appName/readme — the store's own description of a plugin, for the detail
+// pane of something not installed yet.
+//
+// Under `/plugins` so the existing `plugins` permission covers it: reading the store is the same
+// privilege as installing from it, and a second key would be a second thing to grant for no separate
+// decision.
+pluginsRouter.get('/catalogue/:appName/readme', async (ctx) => {
+  const readme = await fetchReadme(ctx.req.param('appName'));
+  return ctx.json({ readme });
+});
+
 pluginsRouter.get('/', async (ctx) => {
   const { states, broken } = await snapshotPlugins();
   // Asked per plugin rather than once, because `pm2 jlist` is a fork and most plugins have no sidecar to
diff --git a/src/servers/plugins/marketplace.ts b/src/servers/plugins/marketplace.ts
index 731ba8ed..08b29007 100644
--- a/src/servers/plugins/marketplace.ts
+++ b/src/servers/plugins/marketplace.ts
@@ -264,6 +264,36 @@ export async function catalogueEntry(appName: string): Promise<CatalogueEntry |
   return all.find((e) => e.appName === appName) ?? null;
 }
 
+/**
+ * A plugin's README, from the marketplace's single-entry endpoint.
+ *
+ * Separate from `fetchCatalogue` because the list endpoint deliberately does not carry READMEs — three
+ * of them is already 38KB of markdown nobody has asked to read, on the request that draws the tiles.
+ *
+ * Fetched by the SERVER rather than by the browser, though CORS would allow either. An Officer client is
+ * routinely somewhere its server is not: a phone on the tailnet, a laptop with the store blocked. The
+ * server has the internet connection that already had to work for the catalogue itself, so routing
+ * through it means the README appears in exactly the cases the plugin list did.
+ *
+ * Null on any failure. A missing README is a section that does not render, never an error state on a
+ * page whose actual job is installing things.
+ */
+export async function fetchReadme(appName: string): Promise<string | null> {
+  try {
+    const res = await fetch(`${MARKETPLACE_URL}/api/plugins/${encodeURIComponent(appName)}`, {
+      signal: AbortSignal.timeout(FETCH_TIMEOUT_MS),
+      headers: { accept: 'application/json' },
+    });
+    if (!res.ok) return null;
+    const body: unknown = await res.json();
+    if (!body || typeof body !== 'object') return null;
+    const readme = (body as { readme?: unknown }).readme;
+    return typeof readme === 'string' && readme.length > 0 ? readme : null;
+  } catch {
+    return null;
+  }
+}
+
 /** Testing seam. The cache is process-lifetime, so a test that does not clear it leaks into the next. */
 export function clearCatalogueCache(): void {
   cache = null;
diff --git a/src/workspaces/officerdev/src/apps/Plugins/PluginDetail.tsx b/src/workspaces/officerdev/src/apps/Plugins/PluginDetail.tsx
index 785283a7..f8e0fe40 100644
--- a/src/workspaces/officerdev/src/apps/Plugins/PluginDetail.tsx
+++ b/src/workspaces/officerdev/src/apps/Plugins/PluginDetail.tsx
@@ -1,5 +1,9 @@
 import { Link, useSearchParams } from 'react-router';
 import { resolveIcon } from '../../utils/resolve-icon';
+import { useQuery } from '@tanstack/react-query';
+import ReactMarkdown from 'react-markdown';
+import remarkGfm from 'remark-gfm';
+import { useClient } from 'hooks/useClient';
 import {
   usePlugins,
   type AvailablePlugin,
@@ -234,9 +238,44 @@ const AvailableDetail = ({
     </div>
 
     <ActionLog steps={steps} result={result} running={running} />
+
+    <Readme appName={plugin.appName} />
   </div>
 );
 
+/**
+ * What the marketplace says about a plugin, in the pane where somebody decides whether to install it.
+ *
+ * Fetched separately from the plugin list on purpose: the list draws tiles and three READMEs is ~38KB of
+ * markdown that nobody has asked to read yet. This request happens when a plugin is actually opened.
+ *
+ * Absence renders NOTHING — no error, no empty state, no spinner left behind. A plugin without a README
+ * is normal, and the store being unreachable must not put a failure message on a page whose job is
+ * installing things. The list itself already degrades; this follows it.
+ *
+ * Styled with `chat-md` — the app's one markdown stylesheet (`styles/prose.css`) — rather than a new
+ * class. The same content should not have two looks in the same application.
+ */
+const Readme = ({ appName }: { appName: string }) => {
+  const { get } = useClient();
+  const { data } = useQuery({
+    queryKey: ['plugins', 'readme', appName],
+    queryFn: () => get<{ readme: string | null }>(`/plugins/catalogue/${appName}/readme`),
+    // The store caches for five minutes server-side; re-reading it on every tab focus would be a
+    // network round trip to redraw identical markdown.
+    staleTime: 5 * 60 * 1000,
+    retry: false,
+  });
+
+  if (!data?.readme) return null;
+
+  return (
+    <section className="chat-md mt-8 border-t border-duck-dark/10 pt-6">
+      <ReactMarkdown remarkPlugins={[remarkGfm]}>{data.readme}</ReactMarkdown>
+    </section>
+  );
+};
+
 export const PluginDetail = () => {
   const { plugins, available, steps, result, running, run } = usePlugins();
   const [params] = useSearchParams();