diff --git a/src/components/insights/mood/__tests__/mood-insights-sections-error-state.test.tsx b/src/components/insights/mood/__tests__/mood-insights-sections-error-state.test.tsx
new file mode 100644
index 000000000..7df15c84d
--- /dev/null
+++ b/src/components/insights/mood/__tests__/mood-insights-sections-error-state.test.tsx
@@ -0,0 +1,53 @@
+/**
+ * The mood-insights regions used to render nothing on a failed read, by
+ * documented intent ("degrades gracefully to the line chart"). The maintainer
+ * decision is to enforce §6 here like everywhere else: a failed read is not an
+ * empty page. The shared query is forced into its error state; the main "rest"
+ * region has to surface a `query-error-row` with retry (mirroring the loading
+ * convention, which also only paints in the "rest" region).
+ */
+import { describe, it, expect, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({
+    user: { id: "u1" },
+    isLoading: false,
+    isAuthenticated: true,
+    error: null,
+    refetch: () => {},
+  }),
+}));
+
+vi.mock("@tanstack/react-query", () => ({
+  useQuery: () => ({
+    data: undefined,
+    isLoading: false,
+    isError: true,
+    refetch: vi.fn(),
+  }),
+}));
+
+import { I18nProvider } from "@/lib/i18n/context";
+import { MoodInsightsSections } from "../mood-insights-sections";
+
+function render(region: "heatmap" | "assessment" | "rest") {
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale="en">
+      <MoodInsightsSections region={region} />
+    </I18nProvider>,
+  );
+}
+
+describe("<MoodInsightsSections> — a read failure is honest, not empty", () => {
+  it("surfaces a query-error row with retry in the rest region", () => {
+    const html = render("rest");
+    expect(html).toContain('data-slot="query-error-row"');
+    expect(html).toContain('data-slot="query-error-row-retry"');
+  });
+
+  it("stays quiet in the heatmap/assessment regions to avoid stacking rows", () => {
+    expect(render("heatmap")).toBe("");
+    expect(render("assessment")).toBe("");
+  });
+});
diff --git a/src/components/insights/mood/mood-insights-sections.tsx b/src/components/insights/mood/mood-insights-sections.tsx
index be65c1124..a5de9a854 100644
--- a/src/components/insights/mood/mood-insights-sections.tsx
+++ b/src/components/insights/mood/mood-insights-sections.tsx
@@ -7,6 +7,7 @@ import { CalendarDays, Sparkles } from "lucide-react";
 
 import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { TileHeader } from "@/components/insights/tile-header";
+import { QueryErrorRow } from "@/components/ui/query-error-row";
 import { Skeleton } from "@/components/ui/skeleton";
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
@@ -100,7 +101,7 @@ export function MoodInsightsSections({
   const { isAuthenticated } = useAuth();
   const { t } = useTranslations();
 
-  const { data, isLoading } = useQuery({
+  const { data, isLoading, isError, refetch } = useQuery({
     queryKey: queryKeys.moodInsights(),
     queryFn: async () => {
       return apiGet<MoodInsightsResponse>("/api/mood/insights");
@@ -118,6 +119,15 @@ export function MoodInsightsSections({
     ) : null;
   }
 
+  if (isError) {
+    // §6 — a failed read is not an empty page. Surface it once, in the main
+    // "rest" region (mirroring the loading convention above), rather than
+    // stacking an identical row in all three regions down the page.
+    return region === "rest" ? (
+      <QueryErrorRow onRetry={() => refetch()} />
+    ) : null;
+  }
+
   if (!data || data.summary.totalEntries === 0) {
     return null;
   }