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"Look at the drawing," said Bean. "Right in the middle, where the bitmap is so complicated-there's one line that's damaged. The dots don't line up at all. It's virtually random."
"It just looks like noise to me."
"If you were being held captive but you had computer access, only every bit of mail you sent out was scrutinized, how would you send a message?" asked Bean.
"You don't think this could be a message from--do you?"
"I have no idea. But now that I've thought of it, it's worth looking don't you think?"
By now Bean had pasted the dragon image into a graphics program and was studying that line of pixels. "Yes, this is random, the whole line. Doesn't belong here, and it's not just noise because the rest of the image is still completely intact except for this other line that's partly broken. Noise would be randomly distributed."
"See what it is, then," said Carlotta. "You're the genius, I'm the nun."
Soon Bean had the two lines isolated in a separate file and was studying the information as raw code. Viewed as one-byte or twobyte text code, there was nothing that remotely resembled language, but of course it couldn't, could it, or it would never have got out. So if it was a message, then it had to be in some kind of code.
For the next few hours Bean wrote programs to help him manipulate the data contained in those lines. He tried mathematical schemes and graphic reinterpretations, but in truth he knew all along that it wouldn't be anything that complex. Because whoever created it would have had to do it without the aid of a computer. It had to be something relatively simple, designed only to keep a cursory examination from revealing what it was.
And so he kept coming back to ways of reinterpreting the binary code as text. Soon enough he came upon a scheme that seemed promising. Two-byte text code, but shifted right by one position for each character, except when the right shift would make it correspond with two actual bytes in memory, in which case double shift. That way a real character would never show up if someone looked at the file with an ordinary view program.
When he used that method on the one line, it came up as text characters only, which was not likely to happen by chance. But the other line came up random-seeming garbage.
So he left-shifted the other line, and it, too, became nothing but text characters. "I'm in," he said. "And it is a message."
"What does it say?"
"I haven't the faintest idea."