Normal sudoku rules apply. The grid is partially covered in fog. Entering correct digits will clear the fog from surrounding cells, possibly revealing more clues. If an arrow is present in a cell, the digit in the cell the arrow comes from appears in the grid in the direction of the arrow at a distance of N cells, where N is the digit in the arrow's cell. Example: If R3C4 had an arrow pointing to the left and R3C4 was a 2, then the digit below that arrow (R4C4) would appear in R3C2 again. Each line in the grid is a palindrome. The sequence of digits along a palindrome read the same from both ends. Each palindrome is a single line in a unique color. Digits in cells that are connected by a white dot are consecutive. Digits in cells that are connected by a black dot are in a 1:2 ratio.