Draw a line around the grid that passes through ALL the black and white dots before joining up with itself to make a continuous loop. Your line can pass through or turn left or right in empty squares, but there are rules for squares containing dots. Your line cannot cross over itself, branch off, or go through the same square twice.
Rules for dots:
Black Dot: Your line must turn left or right in these boxes, and pass straight through the next and previous boxes.
White Dot: Your line must travel straight through the box, and it must turn left or right in the next box and/or the previous box.