Normal sudoku rules apply. Digits an equal distance from the centre of a lavender 'Zipper Line' sum to the digits in the middle of that line. Digits on a white dot are consecutive. Not all dots are given. Nine cells in the grid (one per row, column, and box) are Doublers, which count as double their value on Zipper lines. Each digit appears in exactly one Doubler. Doublers aren't necessarily on Zipper lines.