diff --git a/tests/AcDream.Core.Net.Tests/LiveHandshakeTests.cs b/tests/AcDream.Core.Net.Tests/LiveHandshakeTests.cs
index c5d3f66..44f4258 100644
--- a/tests/AcDream.Core.Net.Tests/LiveHandshakeTests.cs
+++ b/tests/AcDream.Core.Net.Tests/LiveHandshakeTests.cs
@@ -197,12 +197,15 @@ public class LiveHandshakeTests
                           $"inbound.next=0x{new IsaacRandom(serverSeedBytes).Next():X8}, " +
                           $"outbound.next=0x{new IsaacRandom(clientSeedBytes).Next():X8}");
 
-        // Step 4: receive post-handshake traffic. We expect EncryptedChecksum
-        // packets containing CharacterList and friends. If our ISAAC seed is
-        // wrong or our CRC math is off, TryDecode will return ChecksumMismatch.
+        // Step 4: receive post-handshake traffic. Run fragments through a
+        // FragmentAssembler so multi-packet game messages reassemble, then
+        // read the opcode (first 4 bytes of the assembled body) to prove
+        // we're looking at real GameMessage opcodes.
+        var assembler = new FragmentAssembler();
         int postHandshakePackets = 0;
         int successfullyDecoded = 0;
         int checksumFailures = 0;
+        var seenOpcodes = new List<uint>();
         var postDeadline = DateTime.UtcNow + TimeSpan.FromSeconds(5);
         while (DateTime.UtcNow < postDeadline)
         {
@@ -214,13 +217,34 @@ public class LiveHandshakeTests
                               $"decode={decoded.Error}, flags={decoded.Packet?.Header.Flags}, " +
                               $"seq={decoded.Packet?.Header.Sequence}");
             if (decoded.IsOk)
+            {
                 successfullyDecoded++;
+                foreach (var frag in decoded.Packet!.Fragments)
+                {
+                    var completeBody = assembler.Ingest(frag, out _);
+                    if (completeBody is not null && completeBody.Length >= 4)
+                    {
+                        uint opcode = BinaryPrimitives.ReadUInt32LittleEndian(completeBody);
+                        seenOpcodes.Add(opcode);
+                        string name = opcode switch
+                        {
+                            0xF658 => "CharacterList",
+                            0xF7E1 => "ServerName",
+                            0xF7E5 => "DDDInterrogation",
+                            _      => "unknown",
+                        };
+                        Console.WriteLine($"[live]   GameMessage assembled: opcode=0x{opcode:X8} ({name}), " +
+                                          $"body={completeBody.Length} bytes");
+                    }
+                }
+            }
             else if (decoded.Error == PacketCodec.DecodeError.ChecksumMismatch)
                 checksumFailures++;
         }
 
         Console.WriteLine($"[live] step 4 summary: {postHandshakePackets} packets received, " +
-                          $"{successfullyDecoded} decoded OK, {checksumFailures} checksum failures");
+                          $"{successfullyDecoded} decoded OK, {checksumFailures} checksum failures, " +
+                          $"{seenOpcodes.Count} GameMessages assembled");
 
         // The contract of Phase 4.6e is "server accepted our ConnectResponse
         // and started streaming". Any post-handshake traffic at all proves