Katastrophion was kindly provided by *Muddled Puzzles* who make many different types of pure spatial-logic puzzles, all possessing the umbrella brand name Sudokion. The puzzles owe their origin to Sudoku, with its square grid and requirement that every row, column and cluster contain all the set (i.e. all the values — numbers, letters or symbols — of the particular puzzle). But they take the concept much further than Sudoku. All muddled puzzles are the invention of and created by Stephen Jones, co-founder with wife Michele Day of Muddled Puzzles.

Here is the solution to this version of Katastrophion: