Logic Masters Deutschland e.V.

Do killers have friends? Well, at least in this puzzle they do. But, being stealth killers, they must keep their friends secret. Can you reveal the clandestine partnerships?

Rules:

Normal sudoku rules apply. Digits cannot repeat within a cage.
For each cage, there is at least one other cage with the same digit sum.

Play with SudokuPad

NB. This is a remake of an old puzzle of mine that has now been deactivated.