diff --git a/src/main/MazeMain.java b/src/main/MazeMain.java
index 1267841..cb417a9 100644
--- a/src/main/MazeMain.java
+++ b/src/main/MazeMain.java
@@ -5,13 +5,12 @@
 public class MazeMain {
 
     public static void main(String[] args) throws Exception {
-        System.out.println("MazeMain...");
         Cell cell = new Cell(1, 2);
-        System.out.println(cell);
 
         Grid grid = new Grid(10, 10);
-        System.out.println(grid);
+        // System.out.println(grid);
         BinaryTree bt = new BinaryTree(grid);
+        System.out.println(bt.toString());
     }
 
 }
diff --git a/src/main/net/curtlewis/maze/algorithm/BinaryTree.java b/src/main/net/curtlewis/maze/algorithm/BinaryTree.java
index d4cf809..6f50773 100644
--- a/src/main/net/curtlewis/maze/algorithm/BinaryTree.java
+++ b/src/main/net/curtlewis/maze/algorithm/BinaryTree.java
@@ -13,6 +13,7 @@
 
     public BinaryTree(Grid grid) {
         this.grid = grid;
+        init();
     }
 
     private void init() {
@@ -23,15 +24,25 @@
             for(int c = 0; c < cols; c++) {
                 Cell cell = grid.getCellAt(r, c);
                 List<Cell> neighbors = new ArrayList<>();
-                if (cell.getNorth() != null) { neighbors.add(cell); }
-                if (cell.getEast() != null) { neighbors.add(cell); }
+                if (cell.getNorth() != null) { 
+                    neighbors.add(cell.getNorth()); 
+                }
+                if (cell.getEast() != null) { neighbors.add(cell.getEast()); }
 
                 // pick a random cell from the neighbors list
-                Cell neighbor = neighbors.get( new Random().nextInt(neighbors.size()) );
-
-                cell.link(neighbor);
+                if (neighbors.size() > 0) {
+                    int randVal =  new Random().nextInt(neighbors.size());
+                    Cell neighbor = neighbors.get(randVal);
+                    cell.link(neighbor);
+                }
             }
         }
+        
+    }
+
+    public String toString() {
+        System.out.println("Binary Tree Algorithm");
+        return grid.toString();
     }
 
 }
diff --git a/src/main/net/curtlewis/maze/grid/Cell.java b/src/main/net/curtlewis/maze/grid/Cell.java
index 34ad9cb..05044cf 100644
--- a/src/main/net/curtlewis/maze/grid/Cell.java
+++ b/src/main/net/curtlewis/maze/grid/Cell.java
@@ -49,6 +49,7 @@
         if (bidi) {
             cell.link(this, false);
         }
+
     }
 
     public void link(Cell cell) {
diff --git a/src/main/net/curtlewis/maze/grid/Grid.java b/src/main/net/curtlewis/maze/grid/Grid.java
index 9cc1867..878977a 100644
--- a/src/main/net/curtlewis/maze/grid/Grid.java
+++ b/src/main/net/curtlewis/maze/grid/Grid.java
@@ -103,13 +103,14 @@
             String bottom = "+";
 
             for(int c = 0; c < columns; c++) {
-                Cell cell = getCellAt(r, c);
+                Cell sell = getCellAt(r, c);
+                Cell cell =  sell != null ? sell : new Cell(-1, -1);
 
                 String body = "   ";  // <-- 3 spaces
-                String eastBoundary = (cell.hasLink(cell.getEast())) ? " " : "|";
+                String eastBoundary = cell.hasLink(cell.getEast()) ? " " : "|";
                 top = top + body + eastBoundary;
 
-                String southBoundary = (cell.hasLink(cell.getSouth())) ? "   " : "---";
+                String southBoundary = cell.hasLink(cell.getSouth()) ? "   " : "---";
                 String corner = "+";
                 bottom = bottom + southBoundary + corner;
             }