diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorianDataSource.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorianDataSource.cs
index 3b9c1b97..309a0b63 100644
--- a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorianDataSource.cs
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/IHistorianDataSource.cs
@@ -143,8 +143,8 @@ public interface IHistorianDataSource : IDisposable
     ///     </para>
     ///     <para>
     ///         The default forwards a forward read to the five-argument overload and throws
-    ///         <see cref="NotSupportedException"/> for a reverse one — a backend that cannot read newest-first (Gateway,
-    ///         Null). The server never relies on that throw: it consults <see cref="SupportsReverseEvents"/> first and walks
+    ///         <see cref="NotSupportedException"/> for a reverse one — a backend that cannot read newest-first (the
+    ///         Gateway). The server never relies on that throw: it consults <see cref="SupportsReverseEvents"/> first and walks
     ///         such a read back from forward reads (#691.4), never returning the earliest events in ascending order as if
     ///         they were the answer. A backend that serves reverse natively must override BOTH members.
     ///     </para>
diff --git a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/NullHistorianDataSource.cs b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/NullHistorianDataSource.cs
index 9d97b317..811e3dc2 100644
--- a/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/NullHistorianDataSource.cs
+++ b/src/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions/Historian/NullHistorianDataSource.cs
@@ -61,13 +61,12 @@ public sealed class NullHistorianDataSource : IHistorianDataSource
     public bool SupportsReverseRaw => true;
 
     /// <inheritdoc />
-    /// <remarks><c>false</c> (Gitea #675): there is no history to read in either direction; the server walks a reverse
-    /// read back from (empty) forward reads like any backend that cannot read newest-first (#691.4).</remarks>
-    public bool SupportsReverseEvents => false;
+    /// <remarks><c>true</c>, like <see cref="SupportsReverseRaw"/> (Gitea #691.4 review; <c>false</c> under #675): there is no
+    /// history to read in either direction — no need for the server to walk back through empty forward reads.</remarks>
+    public bool SupportsReverseEvents => true;
 
     /// <inheritdoc />
-    /// <remarks>Forward ⇒ the empty result; reverse ⇒ <see cref="NotSupportedException"/>, the interface contract for a
-    /// backend without <see cref="SupportsReverseEvents"/>.</remarks>
+    /// <remarks>The empty result in either direction.</remarks>
     public Task<HistoricalEventsResult> ReadEventsAsync(
         string? sourceName,
         DateTime startUtc,
@@ -75,9 +74,7 @@ public sealed class NullHistorianDataSource : IHistorianDataSource
         int maxEvents,
         bool reverse,
         CancellationToken cancellationToken) =>
-        reverse
-            ? throw new NotSupportedException("The null historian cannot read events newest-first (reverse).")
-            : Task.FromResult(EmptyEvents);
+        Task.FromResult(EmptyEvents);
 
     /// <inheritdoc />
     /// <remarks>
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
index 8488e171..a939ed3c 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaNodeManager.cs
@@ -5291,7 +5291,7 @@ public sealed class OtOpcUaNodeManager : CustomNodeManager2
                 reverse = startUtc > endUtc;
             }
 
-            // A reverse read on a backend that cannot read newest-first (Gateway, Null) is never sent there (#675 refused it
+            // A reverse read on a backend that cannot read newest-first (the Gateway) is never sent there (#675 refused it
             // here); since #691.4 it is walked back from bounded forward reads — the raw walk (#686), with ties ordered by
             // EventId because the gateway orders by event time only. Decided by the capability, not by catching an
             // exception, so a NotSupportedException thrown from inside a backend stays a backend fault.
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/ReverseEventsReader.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/ReverseEventsReader.cs
index 52ab3bfd..f19648d3 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/ReverseEventsReader.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/ReverseEventsReader.cs
@@ -9,7 +9,7 @@ internal readonly record struct ReverseEventsPage(List<HistoricalEvent> Events,
 
 /// <summary>
 ///     Gitea #691.4: serves a Part 11 reverse events read — <c>(lo, hi]</c> newest-first — on a backend that reads events
-///     forward only (<see cref="IHistorianDataSource.SupportsReverseEvents"/> = <c>false</c>: Gateway, Null) with the
+///     forward only (<see cref="IHistorianDataSource.SupportsReverseEvents"/> = <c>false</c>: the Gateway) with the
 ///     <see cref="ReverseWalk"/>. A segment read is cut short when the source flags truncation (its continuation point); ties
 ///     are ordered by <see cref="EventIdTieOrder"/> because the gateway orders by event time only.
 /// </summary>
diff --git a/tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/Historian/NullHistorianDataSourceTests.cs b/tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/Historian/NullHistorianDataSourceTests.cs
index e9045e7b..4c4b1dd7 100644
--- a/tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/Historian/NullHistorianDataSourceTests.cs
+++ b/tests/Core/ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests/Historian/NullHistorianDataSourceTests.cs
@@ -68,17 +68,19 @@ public sealed class NullHistorianDataSourceTests
     }
 
     /// <summary>
-    ///     #675: the direction-aware overload's default — forward is the five-argument read, reverse is refused
-    ///     (the server answers <c>BadHistoryOperationUnsupported</c>).
+    ///     #691.4 review: like raw, the null source reads events in either direction (empty) and says so — the server sends
+    ///     it the reverse read directly instead of walking back through empty forward reads (it refused reverse under #675).
     /// </summary>
     [Fact]
-    public async Task Direction_aware_ReadEventsAsync_forwards_forward_and_refuses_reverse()
+    public async Task Direction_aware_ReadEventsAsync_is_empty_in_both_directions()
     {
         IHistorianDataSource source = Source;
+        source.SupportsReverseEvents.ShouldBeTrue();
         (await source.ReadEventsAsync(null, DateTime.UtcNow.AddHours(-1), DateTime.UtcNow, 0, reverse: false, Ct))
             .Events.ShouldBeEmpty();
-        await Should.ThrowAsync<NotSupportedException>(() =>
-            source.ReadEventsAsync(null, DateTime.UtcNow, DateTime.UtcNow.AddHours(-1), 0, reverse: true, Ct));
+        var reverse = await source.ReadEventsAsync(null, DateTime.UtcNow, DateTime.UtcNow.AddHours(-1), 0, reverse: true, Ct);
+        reverse.Events.ShouldBeEmpty();
+        reverse.ContinuationPoint.ShouldBeNull();
     }
 
     /// <summary>GetHealthSnapshot reports a fully-disabled (zeroed, disconnected, no-node) shape.</summary>