Normal sudoku rules apply. The 3x3 black box borders split grey thermometer lines into segments. Starting from the bulb, the sum of each segment must increase. Additionally, within each segment, starting from the original bulb, digits must also increase. Every 2x2 square of cells completely sitting within a red cage must contain a low digit (1,2,3), middle digit (4,5,6) and high digit (7,8,9). Digits connected by a white dot are consecutive. If a black dot sits between two digits, one is double the other.