diff --git a/MUNGA_L4/L4NET.CPP b/MUNGA_L4/L4NET.CPP
index 6716692..d87784d 100644
--- a/MUNGA_L4/L4NET.CPP
+++ b/MUNGA_L4/L4NET.CPP
@@ -214,7 +214,15 @@ L4NetworkManager::L4NetworkManager():
 		}
 		networkEggNotationFile = new NotationFile(egg_name);
 		Register_Object(networkEggNotationFile);
-		networkEggNotationFile->WriteFile("last.egg");
+		//
+		// NOT last.egg. That name now belongs to the egg saved beside
+		// last.spl for playback, and this is something else entirely - a
+		// debug dump of whatever egg was just loaded. The two collided, and
+		// playback picking this one up as if it were a recording's companion
+		// read a host table of the wrong length out of the spool header,
+		// walked off the end of it, and corrupted the heap.
+		//
+		networkEggNotationFile->WriteFile("last-loaded.egg");
 		currentNetworkState = NormalState;
 
 		ReceiveEggFileMessage egg_message(-1, 10, "local egg", 10);
diff --git a/MUNGA_L4/L4SPLR.cpp b/MUNGA_L4/L4SPLR.cpp
index df356e5..54a4f80 100644
--- a/MUNGA_L4/L4SPLR.cpp
+++ b/MUNGA_L4/L4SPLR.cpp
@@ -367,6 +367,39 @@ void
 		}
 	}
 
+	//
+	// Did the header end where the packets begin?
+	//
+	// The table above holds one pair per host named in the EGG, and the
+	// reader trusts the egg to have as many hosts as the spool was written
+	// with. Hand it a different egg and the count differs, the read pointer
+	// stops short of - or past - the first packet, and every packet after
+	// that is parsed from the middle of something else. The first symptom is
+	// a nonsense message length, and the second is a corrupted heap: exit
+	// 0xC0000374, no message, nothing in the log.
+	//
+	// A packet here should start with a plausible length. If it does not,
+	// the egg does not belong to this spool, and saying so is worth more
+	// than whatever the heap does next.
+	//
+	{
+		NetworkPacket *first = (NetworkPacket*) spool->GetPointer();
+		int first_length = (int) first->messageData.messageLength;
+
+		if (first_length < (int) sizeof(Receiver::Message)
+			|| first_length > 65536
+			|| first_length > (int) spool->GetBytesRemaining())
+		{
+			DEBUG_STREAM << "\n\nError - this egg does not belong to this spool."
+				<< " The host table ran to the wrong length and the first packet"
+				<< " reads as " << first_length << " bytes, which cannot be"
+				<< " right. Play it back with the .egg that was saved beside"
+				<< " it.\n" << std::flush;
+			PostQuitMessage(AbortExitCodeID);
+			return;
+		}
+	}
+
 	//
 	// Now, just send the load message
 	//