diff --git a/plugin-designs/research-dashboard/src/components/dashboards/DashboardChartsRail.vue b/plugin-designs/research-dashboard/src/components/dashboards/DashboardChartsRail.vue
index 664b562f5..3c9da1eaf 100644
--- a/plugin-designs/research-dashboard/src/components/dashboards/DashboardChartsRail.vue
+++ b/plugin-designs/research-dashboard/src/components/dashboards/DashboardChartsRail.vue
@@ -6,11 +6,41 @@
  * click via delegation on the stable container (per-element @click is unreliable in a virtualized/
  * patched defineCustomElement tree). Tweens via CSS (bar width + slice opacity).
  */
-import { inject, computed } from 'vue'
+import { inject, computed, ref } from 'vue'
 import { useShadowStyles } from '@map/composables/useShadowStyles.js'
 import { aggregate, buildDonut, buildBars, lbl, buildCountryRegionColors } from '../../composables/useDashboardAggregations.js'
 import { buildSearchAccessors, makeSearchMatcher } from '../../composables/useDashboardShell.js'
 
+/**
+ * ── THE RAIL'S TAB STRIP ──────────────────────────────────────────────────────────────────────
+ * Charts is selected by default, which is the Driver's wording: "Charts will be a SELECTED TAB
+ * that will show the charts."
+ *
+ * ★ GOSPEL RESOURCES SHIPS DISABLED, NOT HIDDEN, and that is a deliberate choice rather than a
+ * placeholder. Its content is not a separate dataset panel — the Driver described it as the SAME
+ * facet breakdown re-measured on a different axis ("people groups by their gospel resources
+ * availability"), and three decisions about that data are still open: the official lostness number,
+ * whether to stay key-less or register a Joshua Project key, and the UI shape. Guessing any of them
+ * would ship a wrong picture that looks right, which is this codebase's most expensive failure mode.
+ *
+ * A HIDDEN tab is indistinguishable from an unbuilt one. A disabled tab carrying its reason in the
+ * title attribute tells the Driver exactly what it is waiting on, every time he looks at the rail —
+ * which is worth more than the tab being invisible until it is perfect.
+ *
+ * `tabs` is a plain array rather than config-driven on purpose: there are two of them and one is a
+ * stub. Making it configurable now would be an abstraction over a single real case.
+ */
+const tabs = [
+  { id: 'charts', label: 'Charts' },
+  {
+    id: 'gospel',
+    label: 'Gospel Resources',
+    disabled: true,
+    why: 'Waiting on three decisions: the official lostness number, key-less vs a registered Joshua Project key, and the UI shape. See IDEA-GOSPEL-RESOURCES-INTEGRATION-STRATEGY.',
+  },
+]
+const activeTab = ref('charts')
+
 const dash = inject('dashboardData', null)
 const bus = inject('selectionBus', null)
 const cfg = inject('dashboardConfig', {})
@@ -105,7 +135,26 @@ useShadowStyles(`
   .rd-charts::-webkit-scrollbar-track{ background:transparent; }
   .rd-charts::-webkit-scrollbar-thumb{ background:var(--dx-scroll-thumb, #c4c8c0); border-radius:8px; }
   .rd-charts::-webkit-scrollbar-thumb:hover{ background:#9aa197; }
+  /* ★ THE TAB STRIP REPLACES .rd-h, and inherits its exact typography on purpose: weight 700, the
+     --fs-md token, uppercase, .5px tracking. The rail's visual weight is unchanged, so this reads
+     as the same header having gained a second option rather than as new chrome appearing. .rd-h is
+     kept below only because a future rail section may want a plain heading again; it is currently
+     unused in this file and in every other file under research-dashboard/ (checked). */
   .rd-charts .rd-h{ font-weight:700; font-size:var(--fs-md,12px); text-transform:uppercase; letter-spacing:.5px; color:var(--rd-muted, #6d766e); }
+  .rd-charts .rd-tabs{ display:flex; gap:2px; align-items:stretch; border-bottom:1px solid var(--rd-border, #d1d4cd); margin-bottom:6px; }
+  .rd-charts .rd-tab{ appearance:none; background:none; border:none; cursor:pointer;
+    padding:4px 8px 5px; font-family:inherit; font-weight:700; font-size:var(--fs-md,12px);
+    text-transform:uppercase; letter-spacing:.5px; color:var(--rd-muted, #6d766e);
+    border-bottom:2px solid transparent; margin-bottom:-1px; white-space:nowrap; }
+  .rd-charts .rd-tab:hover:not(:disabled){ color:var(--rd-text, #3b463d); }
+  /* The selected tab is the ACCENT underline plus full-strength text — the same signal the facet
+     rail uses for an active row, so one visual language covers both rails. */
+  .rd-charts .rd-tab.on{ color:var(--rd-text, #3b463d); border-bottom-color:var(--rd-accent, #92b195); }
+  /* A disabled tab stays LEGIBLE at .45 rather than being hidden: it is a status report, and its
+     title attribute names the three decisions it waits on. Hiding it would make "not built yet"
+     and "does not exist" look identical. */
+  .rd-charts .rd-tab.off{ opacity:.45; cursor:not-allowed; }
+  .rd-charts .rd-tab:focus-visible{ outline:2px solid var(--rd-accent, #92b195); outline-offset:-2px; }
   /* 10px -> 7px 6px: reclaims ~8px of width per card for the plot area itself. */
   .rd-chart{ border:1px solid var(--rd-line, #d1d4cd); border-radius:var(--r-lg,10px); background:var(--rd-bg, #f3f3f1); padding:7px 6px; }
   .rd-chart .rd-ct{ font-weight:700; font-size:var(--fs-sm,11px); color:var(--rd-ink, #3b463d); margin-bottom:6px; }
@@ -202,7 +251,31 @@ useShadowStyles(`
 
 <template>
   <aside class="rd-charts" data-region="charts-rail" @click="onChartClick">
-    <div class="rd-h">Charts</div>
+    <!--
+      ★ THE RAIL IS A TAB STRIP, NOT A HEADING (Driver: "I asked a long time ago that the chart
+      becomes a tab, so that there are tabs, so that you can have the Gospel Resources tab next to
+      Charts. Charts will be a selected tab that will show the charts.")
+
+      THIS IS HALF THE CARD, DELIBERATELY. The container is buildable now; what the Gospel Resources
+      tab ENCODES is not, because it waits on three open Driver decisions (the official lostness
+      number, key-less vs a registered Joshua Project key, and the UI shape). Building the strip now
+      means the tab exists the moment those land, instead of the whole feature waiting on them.
+
+      So the second tab renders DISABLED with an explicit reason rather than being hidden. A hidden
+      tab is indistinguishable from an unbuilt one; a disabled tab that says why is a status report.
+    -->
+    <div class="rd-tabs" role="tablist" aria-label="Rail views">
+      <button
+        v-for="t in tabs" :key="t.id"
+        class="rd-tab" :class="{ on: activeTab === t.id, off: t.disabled }"
+        role="tab" type="button"
+        :aria-selected="activeTab === t.id ? 'true' : 'false'"
+        :disabled="t.disabled"
+        :title="t.disabled ? t.why : t.label"
+        :data-tab="t.id"
+        @click.stop="!t.disabled && (activeTab = t.id)"
+      >{{ t.label }}</button>
+    </div>
 
     <template v-for="chart in charts" :key="chart.id">
       <div v-if="chart.type === 'donut'" class="rd-chart" :data-chart="chart.facet">