Normal sudoku rules apply. Digits in large circles must appear in the surrounding 2x2 area. Digits separated by white dots are consecutive. Digits separated by black dots have a 2:1 ratio (ie. one is double the other). Not all such dots are shown. Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected and no 2x2 area is fully shaded or unshaded. Digits in caged cells indicate how many cells of the same colour (shaded or unshaded) are seen orthogonally from that position, including itself. The "other" colour blocks vision. All dots lie on the boundary of the Yin-Yang pattern (ie. each dot touches one shaded and one unshaded cell). Finally, the grid is partially covered in fog. Placing correct digits will clear the fog from surrounding cells, possibly revealing more clues.