𝗗𝗲𝗰𝗼𝗻𝘀𝘁𝗿𝘂𝗰𝘁𝗶𝗼𝗻: Place 9 non-overlapping 3x3 boxes in the grid. Fill each cell in a box with a digit from 1-9 such that digits don't repeat in rows, columns or boxes. A cell that is not in any 3x3 box should be left blank but its value for the purposes of the loop/palindrome is zero. 𝗗𝘆𝗻𝗮𝗺𝗶𝗰 𝗙𝗼𝗴: The grid is covered in fog. Placing a correct digit in a cell lifts fog from that cell and possibly other cells; revealing new clues. 𝗪𝗵𝗶𝘀𝗽𝗲𝗿 𝗟𝗼𝗼𝗽: Draw a loop through the centers of some cells that moves orthogonally from cell to cell (never diagonally). The loop may touch itself diagonally, but not orthogonally. Adjacent values along the loop differ by 5 or more. 𝗖𝗶𝗿𝗰𝗹𝗲𝘀: Circles are on the loop and in boxes. Their digit counts the number of loop-cells in their box. 𝗣𝗮𝗹𝗶𝗻𝗱𝗿𝗼𝗺𝗲𝘀: Cells an equal distance to the circled center of a line have the same value.