diff --git a/source/build/include/build.h b/source/build/include/build.h
index c61b66484..120ecfebd 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -428,6 +428,10 @@ int32_t   cansee(int32_t x1, int32_t y1, int32_t z1, int16_t sect1,
                  int32_t x2, int32_t y2, int32_t z2, int16_t sect2);
 int32_t   inside(int32_t x, int32_t y, int sectnum);
 void   dragpoint(int pointhighlight, int32_t dax, int32_t day, uint8_t flags = 0);
+inline void   dragpoint(walltype* pointhighlight, int32_t dax, int32_t day, uint8_t flags = 0)
+{
+	dragpoint(int(pointhighlight - wall), dax, day, 0);
+}
 int32_t try_facespr_intersect(uspriteptr_t const spr, vec3_t const in,
                                      int32_t vx, int32_t vy, int32_t vz,
                                      vec3_t * const intp, int32_t strictly_smaller_than_p);
diff --git a/source/core/version.h b/source/core/version.h
index 1ab4f4fcc..2e71395ab 100644
--- a/source/core/version.h
+++ b/source/core/version.h
@@ -74,7 +74,7 @@ const char *GetVersionString();
 #define MINSAVEVER_SW 13
 #define MINSAVEVER_PS 15
 
-#define SAVEVER_DN3D 11
+#define SAVEVER_DN3D 12
 #define SAVEVER_BLD 11
 #define SAVEVER_SW 13
 #define SAVEVER_PS 15
diff --git a/source/games/duke/src/actors.cpp b/source/games/duke/src/actors.cpp
index 168aa0769..fec099f7a 100644
--- a/source/games/duke/src/actors.cpp
+++ b/source/games/duke/src/actors.cpp
@@ -4276,8 +4276,9 @@ void handle_se20(DDukeActor* actor)
 			}
 		}
 
-		dragpoint(t[1], wall[t[1]].x + x, wall[t[1]].y + l);
-		dragpoint(t[2], wall[t[2]].x + x, wall[t[2]].y + l);
+		auto& wal = actor->temp_walls;
+		dragpoint(wal[0], wal[0]->x + x, wal[0]->y + l);
+		dragpoint(wal[1], wal[1]->x + x, wal[1]->y + l);
 
 		for (int p = connecthead; p >= 0; p = connectpoint2[p])
 			if (ps[p].cursectnum == s->sectnum && ps[p].on_ground)
@@ -4709,9 +4710,10 @@ void handle_se128(DDukeActor *actor)
 {
 	int* t = &actor->temp_data[0];
 
-	auto wal = &wall[t[2]];
+	auto wal = actor->temp_walls[0]; 
+	if (!wal) return; // E4L1 contains an uninitialized SE128 which would crash without this.
 
-//	if (wal->cstat | 32) // this has always been bugged, the condition can never be false.
+	//if (wal->cstat | 32) // this has always been bugged, the condition can never be false.
 	{
 		wal->cstat &= (255 - 32);
 		wal->cstat |= 16;
@@ -4724,15 +4726,16 @@ void handle_se128(DDukeActor *actor)
 //	else return;
 
 	wal->overpicnum++;
-	if (wal->nextwall >= 0)
-		wal->nextWall()->overpicnum++;
+	auto nextwal = wal->nextWall();
+	if (nextwal)
+		nextwal->overpicnum++;
 
 	if (t[0] < t[1]) t[0]++;
 	else
 	{
 		wal->cstat &= (128 + 32 + 8 + 4 + 2);
-		if (wal->nextwall >= 0)
-			wal->nextWall()->cstat &= (128 + 32 + 8 + 4 + 2);
+		if (nextwal)
+			nextwal->cstat &= (128 + 32 + 8 + 4 + 2);
 		deletesprite(actor);
 	}
 }
diff --git a/source/games/duke/src/actors_d.cpp b/source/games/duke/src/actors_d.cpp
index 866d006a1..8fbee700c 100644
--- a/source/games/duke/src/actors_d.cpp
+++ b/source/games/duke/src/actors_d.cpp
@@ -3745,7 +3745,7 @@ void moveeffectors_d(void)   //STATNUM 3
 			}
 			break;
 
-		case 128: //SE to control glass breakage
+		case SE_128_GLASS_BREAKING:
 			handle_se128(act);
 			break;
 
diff --git a/source/games/duke/src/actors_r.cpp b/source/games/duke/src/actors_r.cpp
index e8f5672a9..51f8e1750 100644
--- a/source/games/duke/src/actors_r.cpp
+++ b/source/games/duke/src/actors_r.cpp
@@ -3633,7 +3633,7 @@ void moveeffectors_r(void)   //STATNUM 3
 			}
 			break;
 
-		case 128: //SE to control glass breakage
+		case SE_128_GLASS_BREAKING:
 			handle_se128(act);
 			break;
 
diff --git a/source/games/duke/src/constants.h b/source/games/duke/src/constants.h
index d88db1693..2ada74e68 100644
--- a/source/games/duke/src/constants.h
+++ b/source/games/duke/src/constants.h
@@ -87,6 +87,7 @@ enum
 	SE_48_LIGHT_SWITCH                 = 48,
 	SE_49_POINT_LIGHT                  = 49,
 	SE_50_SPOT_LIGHT                   = 50,
+	SE_128_GLASS_BREAKING              = 128,
 	SE_130                             = 130,
 	SE_131                             = 131,
 };
diff --git a/source/games/duke/src/savegame.cpp b/source/games/duke/src/savegame.cpp
index 924dffe1f..55278b9b1 100644
--- a/source/games/duke/src/savegame.cpp
+++ b/source/games/duke/src/savegame.cpp
@@ -293,7 +293,27 @@ FSerializer& Serialize(FSerializer& arc, const char* keyname, DDukeActor& w, DDu
 			("temp_actor", w.temp_actor, def->temp_actor)
 			("seek_actor", w.seek_actor, def->seek_actor)
 			.Array("temp_data", w.temp_data, def->temp_data, 6)
+			.Array("temo_wall", w.temp_walls, def->temp_walls,2)
+			("temp_sect", w.temp_sect, def->temp_sect)
 			.EndObject();
+
+#ifdef  OLD_SAVEGAME
+		// compat handling
+		if (SaveVersion < 12 && arc.isReading())
+		{
+			if (w.s->picnum == SECTOREFFECTOR)
+			{
+				if (w.s->lotag == SE_20_STRETCH_BRIDGE)
+				{
+					for (int i : {0, 1}) w.temp_walls[i] = &wall[w.temp_data[i+1]];
+				}
+				if (w.s->lotag == SE_128_GLASS_BREAKING)
+				{
+					w.temp_walls[0] = &wall[w.temp_data[2]];
+				}
+			}
+		}
+#endif
 	}
 	return arc;
 }
diff --git a/source/games/duke/src/sectors_d.cpp b/source/games/duke/src/sectors_d.cpp
index 6bca6ec07..f4e71744b 100644
--- a/source/games/duke/src/sectors_d.cpp
+++ b/source/games/duke/src/sectors_d.cpp
@@ -723,7 +723,7 @@ void checkhitwall_d(DDukeActor* spr, int dawallnum, int x, int y, int z, int atw
 					auto spawned = EGS(sn, x, y, z, SECTOREFFECTOR, 0, 0, 0, ps[0].angle.ang.asbuild(), 0, 0, spr, 3);
 					spawned->s->lotag = 128; 
 					spawned->temp_data[1] = 5;
-					spawned->temp_data[2] = dawallnum;
+					spawned->temp_walls[0] = wal;
 					S_PlayActorSound(GLASS_BREAKING, spawned);
 					return;
 				}
diff --git a/source/games/duke/src/sectors_r.cpp b/source/games/duke/src/sectors_r.cpp
index bdf8111da..be7f0ae59 100644
--- a/source/games/duke/src/sectors_r.cpp
+++ b/source/games/duke/src/sectors_r.cpp
@@ -1040,9 +1040,9 @@ void checkhitwall_r(DDukeActor* spr, int dawallnum, int x, int y, int z, int atw
 						wal->nextWall()->cstat = 0;
 
 					auto spawned = EGS(sn, x, y, z, SECTOREFFECTOR, 0, 0, 0, ps[0].angle.ang.asbuild(), 0, 0, spr, 3);
-					spawned->s->lotag = 128; 
+					spawned->s->lotag = SE_128_GLASS_BREAKING; 
 					spawned->temp_data[1] = 2; 
-					spawned->temp_data[2] = dawallnum;
+					spawned->temp_walls[0] = wal;
 					S_PlayActorSound(GLASS_BREAKING, spawned);
 					return;
 				}
@@ -1057,9 +1057,9 @@ void checkhitwall_r(DDukeActor* spr, int dawallnum, int x, int y, int z, int atw
 						wal->nextWall()->cstat = 0;
 
 					auto spawned = EGS(sn, x, y, z, SECTOREFFECTOR, 0, 0, 0, ps[0].angle.ang.asbuild(), 0, 0, spr, 3);
-					spawned->s->lotag = 128;
+					spawned->s->lotag = SE_128_GLASS_BREAKING;
 					spawned->temp_data[1] = 2;
-					spawned->temp_data[2] = dawallnum;
+					spawned->temp_walls[0] = wal;
 					S_PlayActorSound(GLASS_BREAKING, spawned);
 					return;
 				}
diff --git a/source/games/duke/src/spawn.cpp b/source/games/duke/src/spawn.cpp
index 0fa9705f2..a74b060f7 100644
--- a/source/games/duke/src/spawn.cpp
+++ b/source/games/duke/src/spawn.cpp
@@ -796,6 +796,7 @@ void spawneffector(DDukeActor* actor)
 		case SE_20_STRETCH_BRIDGE:
 		{
 			int q;
+			walltype* closewall = nullptr;
 
 			startwall = sectp->wallptr;
 			endwall = startwall + sectp->wallnum;
@@ -803,37 +804,31 @@ void spawneffector(DDukeActor* actor)
 			//find the two most clostest wall x's and y's
 			q = 0x7fffffff;
 
-			for (s = startwall; s < endwall; s++)
+			for (auto& wal : wallsofsector(sectp))
 			{
-				x = wall[s].x;
-				y = wall[s].y;
-
-				d = FindDistance2D(sp->x - x, sp->y - y);
+				d = FindDistance2D(sp->x - wal.x, sp->y - wal.y);
 				if (d < q)
 				{
 					q = d;
-					clostest = s;
+					closewall = &wal;
 				}
 			}
 
-			t[1] = clostest;
+			actor->temp_walls[0] = closewall;
 
 			q = 0x7fffffff;
 
-			for (s = startwall; s < endwall; s++)
+			for (auto& wal : wallsofsector(sectp))
 			{
-				x = wall[s].x;
-				y = wall[s].y;
-
-				d = FindDistance2D(sp->x - x, sp->y - y);
-				if (d < q && s != t[1])
+				d = FindDistance2D(sp->x - wal.x, sp->y - wal.y);
+				if (d < q && &wal != actor->temp_walls[0])
 				{
 					q = d;
-					clostest = s;
+					closewall = &wal;
 				}
 			}
 
-			t[2] = clostest;
+			actor->temp_walls[1] = closewall;
 			StartInterpolation(sect, Interp_Sect_FloorPanX);
 			StartInterpolation(sect, Interp_Sect_FloorPanY);
 			break;
diff --git a/source/games/duke/src/types.h b/source/games/duke/src/types.h
index d83760e95..e70fd75f2 100644
--- a/source/games/duke/src/types.h
+++ b/source/games/duke/src/types.h
@@ -35,6 +35,10 @@ struct DDukeActor
 		int palvals;
 	};
 	int temp_data[6];
+	// Some SE's stored indices in temp_data. For purposes of clarity avoid that. These variables are meant to store these elements now
+	walltype* temp_walls[2]; // SE20 + SE128
+	sectortype* temp_sect;
+	
 	DDukeActor* temp_actor, *seek_actor;
 	spritetype* s;	// direct reference to the corresponding sprite.