Normal sudoku rules apply. Along thermometers, digits must increase from the bulb end. In cages, digits must sum to the small clue in the top left corner of the cage. Arrowed clues outside the grid give the sum of the digits on the indicated diagonal. The (unarrowed) 21 clue outside the grid is the sum of the digits sandwiched between the 1 and 9 in its column. Cells separated by a white dot must contain consecutive digits. Not all possible white dots are given.