Normal sudoku rules apply. Digits in a cage sum to the total shown. A clue outside the grid is the sum of the digits between two ‘crusts’ in that row/column. The crusts are determined by the row or column the clue is. For example, if the clue is in row 2 then the sandwich crusts are 2 and 8; if the clue is in column 7 then the sandwich crusts are 7 and 3 (the crusts will sum to 10). All sandwich fillings are in their own Killer Cages.