diff --git a/src/GameCult.Networking/CultNetDatabase.cs b/src/GameCult.Networking/CultNetDatabase.cs
index 083d309f..07336488 100644
--- a/src/GameCult.Networking/CultNetDatabase.cs
+++ b/src/GameCult.Networking/CultNetDatabase.cs
@@ -1922,6 +1922,8 @@ namespace GameCult.Networking
         private CultNetShardDescriptor ResolveShardInternal(CultDocumentDescriptor descriptor, CultRecordKey key) =>
             FindShard(descriptor, key) ?? throw new CultNetUnownedSchemaException(descriptor.SchemaId, key);
 
+        internal bool Owns(CultDocumentDescriptor descriptor, CultRecordKey key) => FindShard(descriptor, key) != null;
+
         private CultNetShardDescriptor? FindShard(CultDocumentDescriptor descriptor, CultRecordKey key) =>
             _shards.FirstOrDefault(shard => shard.Matches(descriptor, key));
 
diff --git a/src/GameCult.Networking/CultNetDatabaseServer.cs b/src/GameCult.Networking/CultNetDatabaseServer.cs
index d53315ed..78124acc 100644
--- a/src/GameCult.Networking/CultNetDatabaseServer.cs
+++ b/src/GameCult.Networking/CultNetDatabaseServer.cs
@@ -135,6 +135,8 @@ namespace GameCult.Networking
                 // R-Q: asOf is one shard-log watermark, so a selection whose matched rows span more than
                 // one shard's log is refused rather than answered against a watermark that is not
                 // exact for all of them.
+                // A row whose schema no shard owns is not part of what this database serves: it is left out, not an error.
+                rowFilter: _database.Owns,
                 shardIdOf: (schemaId, key) => _database.ResolveShard(schemaId, key).ShardId,
                 cursorKey: _database.CursorKey,
                 // S-9: once the matched rows resolve to one shard, asOf is that shard's own watermark,
diff --git a/src/GameCult.Networking/CultNetDocumentRegistry.cs b/src/GameCult.Networking/CultNetDocumentRegistry.cs
index eb23d503..a47f28b3 100644
--- a/src/GameCult.Networking/CultNetDocumentRegistry.cs
+++ b/src/GameCult.Networking/CultNetDocumentRegistry.cs
@@ -338,6 +338,7 @@ namespace GameCult.Networking
         /// row's ordinal (the reference: <see cref="CultNetDatabase.LastWriteSequence"/>); <paramref name="asOf"/>
         /// is the snapshot the page is exact for when the selection is not shard-scoped, or the fallback
         /// used only when <paramref name="asOfForShard"/> is null or the selection matches no rows (S-9).
+        /// <paramref name="rowFilter"/>, when supplied, leaves out the cached rows it rejects before evaluation.
         /// </summary>
         public CultNetSnapshotResponseRawV1Message CreateSelectionResponse(
             CultCache cache,
@@ -348,13 +349,14 @@ namespace GameCult.Networking
             CultNetDocumentMessageOptions? options = null,
             Func<string, CultRecordKey, string>? shardIdOf = null,
             CultNetSelectionCursorKey? cursorKey = null,
-            Func<string, ulong>? asOfForShard = null)
+            Func<string, ulong>? asOfForShard = null,
+            Func<CultDocumentDescriptor, CultRecordKey, bool>? rowFilter = null)
         {
             if (cache == null) throw new ArgumentNullException(nameof(cache));
             if (selection == null) throw new ArgumentNullException(nameof(selection));
             if (ordinalOf == null) throw new ArgumentNullException(nameof(ordinalOf));
 
-            var page = SelectPage(cache, selection, ordinalOf, asOf, options, shardIdOf: shardIdOf, cursorKey: cursorKey, asOfForShard: asOfForShard);
+            var page = SelectPage(cache, selection, ordinalOf, asOf, options, rowFilter, shardIdOf, cursorKey, asOfForShard);
             return new CultNetSnapshotResponseRawV1Message
             {
                 MessageId = RequireNonEmpty(messageId, nameof(messageId)),
diff --git a/tests/GameCult.Networking.Tests/CultNetJournalTests.cs b/tests/GameCult.Networking.Tests/CultNetJournalTests.cs
index 5e18bcd7..3bbb72ef 100644
--- a/tests/GameCult.Networking.Tests/CultNetJournalTests.cs
+++ b/tests/GameCult.Networking.Tests/CultNetJournalTests.cs
@@ -745,6 +745,27 @@ namespace GameCult.Networking.Tests
             Assert.That(cache.Get<MeshQuickstartNote>(Unowned), Is.Null);
         }
 
+        // One cached row of a schema no shard owns is not part of what this database serves: the selection answers with the
+        // rest, it does not fail as a whole.
+        [Test]
+        public async Task ASelectionSkipsACachedRowNoShardOwnsAndAnswersWithTheRest()
+        {
+            var (database, cache, _, _) = OwnedNothingOfNote();
+            await database.PutAsync(One, Note("owned"));
+            await cache.UpsertAsync(new MeshQuickstartNote { NoteId = "u", Body = "unowned" }, new CultRecordHandle<MeshQuickstartNote>(Unowned));
+            using var server = new Server(cache, ServerSecurityOptions.Development());
+            using var databaseServer = new CultNetDatabaseServer(server, database);
+
+            var response = databaseServer.CreateSelectionResponse(new CultNetSnapshotRequestV1Message
+            {
+                MessageId = "select-all",
+                Selection = new CultNetSelection { Projection = CultNetSelectionProjections.Document }
+            });
+
+            Assert.That(response.Documents!.Select(document => document.RecordKey), Is.EqualTo(new[] { One.Value }));
+            Assert.That(response.Matched, Is.EqualTo(1u));
+        }
+
         private sealed class CapturingLogger : GameCult.Logging.ILogger
         {
             public List<string> Errors { get; } = new();