diff --git a/site/src/components/ActivityDetailLoader.svelte b/site/src/components/ActivityDetailLoader.svelte
index 91cd3f9..857864e 100644
--- a/site/src/components/ActivityDetailLoader.svelte
+++ b/site/src/components/ActivityDetailLoader.svelte
@@ -7,9 +7,20 @@
 
   export let base: string = '/';
 
-  let activity: ActivitySummary | null = null;
-  let notFound = false;
-  let loading = true;
+  // Synchronous init — check sessionStorage before first render so "Loading activity…"
+  // is never shown when navigating from the feed.
+  const _activityId = window.location.pathname.match(/\/activity\/([^/]+)/)?.[1] ?? null;
+  let _initial: ActivitySummary | null = null;
+  if (_activityId) {
+    try {
+      const c = sessionStorage.getItem(`bincio:activity:${_activityId}`);
+      if (c) _initial = JSON.parse(c);
+    } catch {}
+  }
+
+  let activity: ActivitySummary | null = _initial;
+  let notFound = _activityId === null;
+  let loading = _activityId !== null && _initial === null;
 
   /**
    * Build an ActivitySummary stub from a detail JSON object.
@@ -85,11 +96,9 @@
   }
 
   onMount(async () => {
-    // Extract activity ID from the URL path: /activity/{id}/
-    const match = window.location.pathname.match(/\/activity\/([^/]+)/);
-    const id = match?.[1];
-    if (!id) { notFound = true; loading = false; return; }
+    if (!loading) return;  // fast path: summary already from sessionStorage
 
+    const id = _activityId!;
     try {
       // Load only the most-recent year shard — avoids downloading all years just
       // to look up one activity. Falls back to a direct file fetch if not found.
diff --git a/site/src/components/ActivityFeed.svelte b/site/src/components/ActivityFeed.svelte
index 619cd51..c30bf30 100644
--- a/site/src/components/ActivityFeed.svelte
+++ b/site/src/components/ActivityFeed.svelte
@@ -350,6 +350,7 @@
               <a
                 href={a.detail_url ? `${import.meta.env.BASE_URL}activity/${a.id}/` : `${import.meta.env.BASE_URL}activity/local/?id=${a.id}`}
                 class="before:absolute before:inset-0 before:content-[''] truncate"
+                on:click={() => { try { sessionStorage.setItem(`bincio:activity:${a.id}`, JSON.stringify(a)); } catch {} }}
               >{a.title}</a>
             </h3>
           </div>