Each column contains the digits 1-9 once (with no repeats), plus one empty cell (which can be shaded green when found). Additionally, no digit may be repeated along any diagonal. However, digits may be repeated within a row. One of the columns is magic. Each digit in the magic column tells you how many times that digit appears in its row. Eg: the 3 in the magic column has exactly three 3s in its row (including itself.) Digits along a thin blue line always add up to 10. Blue lines never pass through any empty cells.