Logic Masters Deutschland e.V.

A sequel to my similarly themed puzzles Killer Duo and Killer Trio. This time, there are four secret cage totals and an extra rule that might be crucial in solving the puzzle. Have fun!

Rules:

Normal sudoku rules apply. Digits cannot repeat within a cage. Digit sums of the cages may have at most four distinct values. Adjacent cages must have different digit sums.

Solve at F-Puzzles or CtC

The break-in may be quite difficult to find. Here are some hints (highlight white text to read):

Hint 1:

The three “islands” are weak alone but strong together.

Hint 2:

A quartet is more than the sum of its parts – but try to figure out the sum first!

Hint 3:

To determine the sum, compare an area with large cages with one with small cages.