Level 844 has a unique challenge. Care has to be taken when playing tiles in the lower right corner. There are 3 tiles at the bottom of the rightmost column. When they are played without spreading cheese the third tile up becomes an empty space. It could happen by blasting any of the 3 tiles. It could happen when playing any of the 3 tiles in a word. The empty space must then be blasted. A line blaster will spread cheese to the first tile in its path(in each direction). The R at the top and the empty space become cheesed by the blaster A.