# Batman and the grid

This a sequel to: Batman and the piano

Master Bruce has received three items, in the mail, from none other than Edward Nigma.

One item is a piece of paper with a grid of dots in an arrangement of 10 dots wide by 12 dots high.
It looks like this:

The second is a slip of paper that simply states:

75 67 67 63 66 3a 2f 2f 74 62 62 2e 74 79 2f 38 66 4c 4c 53 37


The third is a note that states:

Dear Detective,

I hope this finds you well. I'm sure you've been anxious for our next game together. I've placed a bomb somewhere in Gotham. You have one chance to figure out where it is!! You must send this letter back to me with the correct location circled on the grid. If it is incorrect, the bomb will go off! If, by some miracle, you're correct - then perhaps we'll have another game to play together, some day!

Good Luck!

E. Nigma

Perhaps you people can once again help us? This one may take a little time, but I do not know how much of it we have.

• Is batman a detective? Apr 1, 2016 at 17:19
• @Raystafarian Yes...sometimes referred to as even better detective than Sherlock Holmes Apr 1, 2016 at 17:20
• Just send it back how it is. All the locations are circled already. Apr 1, 2016 at 19:33
• The 21 instructions in the "spectrogram" results, they are related to the 21 numbers in the slip of paper, right? I am still thinking about how I should decode the slip to have a clear clue here...
– Mizu
Apr 1, 2016 at 22:32

Is it 2 from the left, 7 from top ?

Decoding the track from Deusovi's answer using by calculating its "spectrogram". For people who know about signal analysis, it is basically using the Fourier transform of each of many finite pieces of the signal, then putting all those results in a stack. This gives a spectrogram, and when plotted with a color scale, it gives the posted result.

left 3 in german; right 4 in german; left 3 in italian; up 7 in german
right 4 in english; left 1 in german; left 5 in italian; left 6 in french; right four in english

EDIT: Actually forgot to analyze the other of the two stereo tracks:

Mixing the two:

UP 2 RIGHT 4 UP 6 RIGHT 4 UP 7 2
LEFT 3 DOWN 3 LEFT 3 UP 4 RIGHT 4
DOWN 8 RIGHT 3 UP 2 LEFT 6 UP 1
RIGHT 4 DOWN 5 LEFT 5 UP 5
LEFT 1 DOWN 1

Tracing this on the dotted graph:

There is only one way as it touches all borders.

• I see what you did but it's probably not obvious to most people - can you explain the method? Apr 1, 2016 at 18:22
• How'd you decode it? Apr 1, 2016 at 18:22
• putting all these together is up 10 and right 1. Not sure where we start though, but I would guess that it's near the bottm
– Matt
Apr 1, 2016 at 19:26
• Note that two of the French bits can be understood as "until" instead of "up". My German is not very good by the way. Apr 1, 2016 at 19:46
• Ah. That appears to be correct, thank you. I shall send this on to Batman to aid in his current search for the bomb. Apr 2, 2016 at 0:16