In this magic square, one of the cells contains what looks like the word DO (that's a letter O), which, by the rules, represents thirteen times whatever the base is, plus twenty-four.
Not only does the word DO appear as one of the numbers in the grid, but also the number representations in the bottom row, if concatenated together, form the word MAGIC.
What is this magic square?
Click here to see the original New Scientist Enigma No. 1680 version of this puzzle.