diff --git a/tests/GameCult.Networking.Tests/SelectionWireParityTests.cs b/tests/GameCult.Networking.Tests/SelectionWireParityTests.cs
index 35e59d2c..cc79fd87 100644
--- a/tests/GameCult.Networking.Tests/SelectionWireParityTests.cs
+++ b/tests/GameCult.Networking.Tests/SelectionWireParityTests.cs
@@ -24,6 +24,7 @@ namespace GameCult.Networking.Tests
         private const string CiterId = "sha256:9d0bc9aebc3619b07aabf564f98667afde41444c1b866661d777687d443608dc";
 
         private const string RustHeaderWithTagsHex = "8AA8736368656D614964D9477368613235363A66663335663364396436646533663130363662393336396537336665366337363438653838333638643138656663323237356339393437333063643834636666AA736368656D614E616D65C0AD736368656D6156657273696F6EC0B1736368656D61436F6E74656E7448617368C0A97265636F72644B6579A4612D6571A873746F7265644174B8313937302D30312D30315430303A30303A30302E3030305AAF736F7572636552756E74696D654964C0AD736F757263654167656E744964C0AA736F75726365526F6C65C0A47461677392A5616C706861A462657461";
+        private const string RustEdgeAllAbsentHex = "85A466726F6D82A8736368656D614964D9477368613235363A39643062633961656263333631396230376161626635363466393836363761666465343134343463316238363636363164373737363837643434333630386463A97265636F72644B6579A763697465722D31A4726F6C65A644657369676EA2746F82A8736368656D614964D9477368613235363A66663335663364396436646533663130363662393336396537336665366337363438653838333638643138656663323237356339393437333063643834636666A97265636F72644B6579A4612D6571AF7061796C6F6164456E636F64696E67C0A77061796C6F6164C0";
         private const string RustEdgeWithPayloadHex = "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";
         private const string RustEnvelopeAllAbsentHex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
 
@@ -42,6 +43,25 @@ namespace GameCult.Networking.Tests
                 "string[] Tags must encode to the same bytes cultnet-rs's Vec<String> tags does");
         }
 
+        [Test]
+        public void EdgeAllAbsentMatchesTheConstantCommittedIntoTheRustTest()
+        {
+            // R-AZ (docs/cultnet-selection-cut.md, "Soul, the merge gate, fourth pass"): the
+            // 246-byte all-absent Edge vector existed only on the Rust side (SM-10). The all-absent
+            // header is covered incidentally because it is nested inside the 376-byte envelope test
+            // above; the edge has no such cover, so a C# edge encoder that resumed omitting a null
+            // payload/payloadEncoding would pass every other test here and still diverge from Rust.
+            var edge = new CultNetEdge
+            {
+                From = new CultNetRecordRef { SchemaId = CiterId, RecordKey = "citer-1" },
+                Role = "Design",
+                To = new CultNetRecordRef { SchemaId = LeafA, RecordKey = "a-eq" }
+            };
+            var hex = Convert.ToHexString(MessagePackSerializer.Serialize(edge, CultNetSchemaMessageSerialization.Options));
+            Assert.That(hex, Is.EqualTo(RustEdgeAllAbsentHex),
+                "an all-absent Edge (PayloadEncoding/Payload both null) must encode to the same bytes cultnet-rs's all-absent Edge does");
+        }
+
         [Test]
         public void EdgeWithPayloadMatchesTheConstantCommittedIntoTheRustTest()
         {