Place 1-9 in each row, column and marked region. All instance of five of the nine digits, to be determined, constitute an area of orthogonal cells, a ‘labyrinth’. The other four digits are considered to be ‘wall’ cells. An arrow appears in a ‘dead end’ of the labyrinth pointing to the only way out, ie. the only labyrinth cell to which it is connected. a 2x2 square containing only labyrinth has a blank square in the middle; a 2x2 square containing only wall cells has a black square in the middle. An X joins two cells that sum to 10, a white dot two consecutive digits, but only if those two cells include one in the labyrinth and one in the wall. All arrows, Xs, white dots and squares are given.