Normal sudoku rules apply. Each wooden stake (line) sums to either 16 or 17. Each grave (cage) sums to the value shown. There are 9 vampires (digits 1-9 once each) in the grid; one in each row, column and box. There are also 9 victims (digits 1-9 once each) in the grid; one in each row, column and box. For purposes of cage and line totals: (a) vampire cells have a value equal to the sum of their digit plus the digit of the victim cell in their box, and (b) victim cells have a value of 0.