diff --git a/Plague.g1a b/Plague.g1a
index 8fd3ccb..4f80122 100644
Binary files a/Plague.g1a and b/Plague.g1a differ
diff --git a/src/data.c b/src/data.c
index cf6bfb5..3042fad 100644
--- a/src/data.c
+++ b/src/data.c
@@ -58,7 +58,7 @@ const struct mutation default_value = {0, 0, 0, 0, 0, "NONE"};
     2: temperate
     3: hot
 */
-const unsigned int world[64][128] =
+const uint8_t world[64][128] =
 {
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
diff --git a/src/display_engine.c b/src/display_engine.c
index e58d63f..7bb4f05 100644
--- a/src/display_engine.c
+++ b/src/display_engine.c
@@ -8,7 +8,7 @@
 void display_background(const int background)
 {
     extern const bopti_image_t img_bground;
-    if (background != 6) dsubimage(0, 0, &img_bground, 0, 65 * (background - 1), 128, 64, DIMAGE_NONE);
+    dsubimage(0, 0, &img_bground, 0, 65 * (background - 1), 128, 64, DIMAGE_NONE);
 }
 
 
@@ -16,7 +16,7 @@ void display_foreground(const int background, const struct game *current_game)
 {
     extern const bopti_image_t img_mutations;
     extern const bopti_image_t img_planes;
-    extern const unsigned int world[64][128];
+    extern const uint8_t world[64][128];
 
     GUNUSED int length;
 
@@ -29,7 +29,7 @@ void display_foreground(const int background, const struct game *current_game)
             {
                 for (int j = 0; j < current_game->grid.height; j ++)
                 {
-                    if (current_game->grid.data[i + j * current_game->grid.width] == 1 && world[i][j] != 0) dpixel(i, j, C_BLACK);
+                    if (current_game->grid.data[i + j * current_game->grid.width] == 1 && world[j][i] != 0) dpixel(i, j, C_BLACK);
                 }
             }
 
@@ -45,9 +45,9 @@ void display_foreground(const int background, const struct game *current_game)
             // Disease propagation
             for (int i = 0; i < current_game->grid.width; i ++)
             {
-                for (int j = 0; j < 50; j ++)
+                for (int j = 0; j < 48; j ++)
                 {
-                    if (current_game->grid.data[i + j * current_game->grid.width] == 1 && world[i][j] != 0) dpixel(i, j, C_BLACK);
+                    if (current_game->grid.data[i + j * current_game->grid.width] == 1 && world[j][i] != 0) dpixel(i, j, C_BLACK);
                 }
             }
 
@@ -88,11 +88,9 @@ void display_foreground(const int background, const struct game *current_game)
         case 6:
             for (int i = 0; i < 4; i ++)
             {
-                // length = 63 * current_game->humans[i] / (current_game->grid.width * current_game->grid.height);
-                // dline(61, i*8 + 31, 61 + length, i*8 + 31, C_BLACK);
-                // dline(61, i*8 + 32, 61 + length, i*8 + 32, C_BLACK);
-                dprint(61, i*8 + 31, C_BLACK, "%d", current_game->humans[i]);
-
+                length = 63 * current_game->humans[i] / (current_game->grid.width * current_game->grid.height);
+                dline(61, i*8 + 31, 61 + length, i*8 + 31, C_BLACK);
+                dline(61, i*8 + 32, 61 + length, i*8 + 32, C_BLACK);
             }
             break;
     }
diff --git a/src/epidemic_engine.c b/src/epidemic_engine.c
index d15b50b..51ca43a 100644
--- a/src/epidemic_engine.c
+++ b/src/epidemic_engine.c
@@ -1,4 +1,5 @@
 #include <gint/std/stdlib.h>
+
 #include "epidemic_engine.h"
 
 
@@ -11,12 +12,12 @@ int grid_get(const struct grid epidemic_grid, const int i, const int j)
 
 bool can_become_infected(const struct grid epidemic_grid, const int mutations_selected[3], const int i, const int j)
 {
-    extern const unsigned int world[64][128];
+    extern const uint8_t world[64][128];
 
     // In case of water, low or high temperature
-    /*if (world[j][i] == 0 && mutations_selected[2] != 3) return false;
+    if (world[j][i] == 0 && mutations_selected[2] != 3) return false;
     if (world[j][i] == 1 && mutations_selected[1] != 0 && mutations_selected[1] != 4) return false;
-    if (world[j][i] == 3 && mutations_selected[1] != 1 && mutations_selected[1] != 4) return false;*/
+    if (world[j][i] == 3 && mutations_selected[1] != 1 && mutations_selected[1] != 4) return false;
     
     // Test cases around
     return grid_get(epidemic_grid, i - 1, j) == 1 || grid_get(epidemic_grid, i + 1, j) == 1 || grid_get(epidemic_grid, i, j - 1) == 1 || grid_get(epidemic_grid, i, j + 1) == 1;
@@ -25,7 +26,7 @@ bool can_become_infected(const struct grid epidemic_grid, const int mutations_se
 
 bool bernoulli(const int p)
 {
-    return (rand() % 101) <= p;
+    return (rand() % 101) < p;
 }
 
 
@@ -33,15 +34,17 @@ void epidemic_simulation(struct game *current_game)
 {
     srand(15510);
 
+    // Create a copy of the epidemic grid
+    uint8_t *current_grid = calloc(current_game->grid.width * current_game->grid.height, sizeof(uint8_t));
+    init_tab(current_game->grid.width * current_game->grid.height, current_grid, current_game->grid.data);
+
     int healed_rate =  100 * (current_game->research / current_game->limit);
 
+    // Make the epidemic grid evolove
     for (int i = 0; i < current_game->grid.width; i ++)
     {
         for (int j = 0; j < current_game->grid.height; j ++)
         {
-            current_game->grid.data[i + j * current_game->grid.width] = 1;
-        
-            /*
             switch (current_game->grid.data[i + j * current_game->grid.width])
             {
                 // Healthy
@@ -50,7 +53,7 @@ void epidemic_simulation(struct game *current_game)
                     // Become infected
                     if (can_become_infected(current_game->grid, current_game->mutations_selected, i, j) && bernoulli(current_game->contagion))
                     {
-                        current_game->grid.data[i + j * current_game->grid.width] = 1;
+                        current_grid[i + j * current_game->grid.width] = 1;
                         current_game->humans[0] --;
                         current_game->humans[1] ++;
                     }
@@ -62,7 +65,7 @@ void epidemic_simulation(struct game *current_game)
                     // Become healed
                     if (bernoulli(healed_rate))
                     {
-                        current_game->grid.data[i + j * current_game->grid.width] = 2;
+                        current_grid[i + j * current_game->grid.width] = 2;
                         current_game->humans[1] --;
                         current_game->humans[2] ++;
                     }
@@ -70,13 +73,24 @@ void epidemic_simulation(struct game *current_game)
                     // Become dead
                     else if (bernoulli(current_game->lethality))
                     {
-                        current_game->grid.data[i + j * current_game->grid.width] = 3;
+                        current_grid[i + j * current_game->grid.width] = 3;
                         current_game->humans[1] --;
                         current_game->humans[3] ++;
                     }
                     break;
-            }*/
+            }
 
         }
     }
+    init_tab(current_game->grid.width * current_game->grid.height, current_game->grid.data, current_grid);
+    free(current_grid);
 }
+
+
+void init_tab(int x, uint8_t dest[x], uint8_t src[x])
+{
+    for (int i = 0; i < x; i++)
+    {
+        dest[i] = src[i];
+    }
+}
\ No newline at end of file
diff --git a/src/epidemic_engine.h b/src/epidemic_engine.h
index a2cdd80..6ad86d3 100644
--- a/src/epidemic_engine.h
+++ b/src/epidemic_engine.h
@@ -15,4 +15,7 @@ bool bernoulli(const int p);
 // epidemic_simulation : simulate the propagation of the virus
 void epidemic_simulation(struct game *current_game);
 
+// init_tab : copy src into dest (for int)
+void init_tab(int x, uint8_t dest[x], uint8_t src[x]);
+
 #endif /* _EPIDEMIC_ENGINE_H */
\ No newline at end of file