Dennis and Effie had spent quite some time working on the package that Hiro's new digital fairy had left for them. After the virus incident, they'd taken the precaution of getting a patch from emergence.org for their editors to separate the debugging facilities from the data-editing facilities unless they explicitly said otherwise, so there was no risk of accidentally letting it execute. After that, though, came the difficult question of what it was supposed to do.
By the early evening, Effie had gotten pretty exasperated with the whole thing. She slapped her editor down onto the coffee table they were sitting on in annoyance; even though there was no way for a virtual object to actually interact with the real, physical surface, in her perception it made a satisfyingly cathartic thwack.
"I don't get it!" she sighed, flopping back onto the table a bit melodramatically. "I know I'm not an expert on protein sequences - by a long shot - but it just doesn't seem to be anything! We've looked through every online guide we could find, and it still just looks like a jumble of discrete proteins that've been glued together for no reason...it's just a sequence of gibberish!"
Dennis nodded. "I hate to say it, but you're right. I just...I don't understand. If the virus was going to pull off one last act, why would it make a packet of gibberish? Before that it was trying to send something out over the wireless, that at least made sense..."
Effie frowned and nodded, and the two of them sat in relative silence for a minute, with only the sounds from the cartoon Mikey was watching filling the air. Then Effie perked up. "Hey," she said, sitting back up. "Packet of gibberish. Packet. What if it's not meant to be a meaningful protein sequence? When we cut it off from the wireless, what if what it was trying to send..."
"...it shoved into Hiro's sequencer?" Dennis finished. "Huh, that's a thought. But why do that? How could they get it back? I mean, it's not like whoever wrote this could just reach into Hiro's body and fish out a specific protein sequence anytime they wanted, even if they knew his physical location."
Effie nodded. "I don't get that either," she said. "All the same, maybe it was a last-ditch attempt to preserve the data...it's certainly big enough." She picked up her editor and opened up the package for inspection. "We should've guessed this earlier," she said. "It's got all twenty-six amino acids with a single-letter abbreviation, plus another six common ones. That's 32, that's a power of two. That should've been conspicuous enough to clue us in..."
"Hey, yeah," Dennis mused. "Still, I don't think we can be too hard on ourselves for not thinking of this. It's not exactly intuitive. Well, except for the part where we got the idea through intuition, I guess."
Effie smiled at that. "Okay," she said. "So thirty-two distinct symbols is five bits per symbol - like uuencode, basically. I think it's a pretty safe guess that the lettered ones we can put in a sequence at the start of the set...I'm not sure how we're supposed to order the other six, I guess we'll play around with that."
"Five bits per symbol...it's a long freaking protein sequence, but it's actually kind of a small piece of data," Dennis mused. "I wonder what they were sending?"
Effie shrugged. "No idea...guess we'll find out. There's 720 possible orderings for the last six, I don't want to try every one of them if we don't have to. We'll just assume that Hiro's sequencer orders them alphabetically for a start." She tapped out a quick little script to do the conversion and set it going, and it spat out a little binary blob into a new tab in her editor. She switched over to look - it didn't seem to be anything. She sighed, then smacked her palm to her for head. "Gah, I hate big-endian systems," she muttered, and ran another script to convert it for legibility. This time...
"Huh," she muttered. Dennis came over to look over her shoulder. "Find anything?" he asked. She nodded. "Yeah, that's an IP header, all right. And a TCP header after. It just jammed the whole packet into the sequencer - oh hey, it's set to broadcast, too. That's nuts."
"No kidding," Dennis said. "Why would you break into a system for something and then broadcast it to every single system on the network? With that and sequencing it...I dunno, it's like they cared less about getting it to their machine than just making sure the information went somewhere."
Effie nodded. "As for the data..." She scrolled a little further down.
4E 55 4D 42 45 52 20 54 48 52 45 45 3A 20 48 55 NUMBER THREE: HU
4D 41 4E 20 46 45 4D 41 4C 45 2C 20 49 44 45 4E MAN FEMALE, IDEN
54 49 46 49 43 41 54 49 4F 4E 20 55 4E 4B 4E 4F TIFICATION UNKNO
57 4E 20 41 54 20 50 52 45 53 45 4E 54 2E 0A 00 WN AT PRESENT...
She stared, open-mouthed. "They didn't even bother to encrypt it?" There was more data after that, but it was plain binary - but for there to be plain, unencrypted ASCII text just sitting right there for the taking - anybody with a packet-sniffer could've found this if it'd ever succeeded in broadcasting this, and been able to read it without even having to make a guess at a key...heck, she could think of a half-dozen simple methods off the top of her head that would be a million times more secure!
Dennis frowned. "Maybe they were counting on it not meaning anything to anybody who stumbled across it. I mean, we were there, and even we don't know who they are. We sure don't have any idea what 'number three' means to them...I wonder what the rest of the data is?"
Effie shrugged. "Not sure...doesn't look like executable code to me." She skimmed over it - huh, that was interesting. There was some regularity to it, the same broad swaths of the same bytes at pretty regular intervals, interrupted by much more random values...reminded her of...she brightened. "It's a picture!" she said, snapping her fingers. She ran over it again, sizing up the section. "It's almost a square number of bits," she said. "So if we display it..." She opened up the image tool in her editor and dragged that section of data over, punching in the dimensions that would fit. The image editor for some reason assumed it was monochrome, leaving a large field of noise...but not wholly irregular noise. It seemed like the lines were too wide for the image and wrapped around, like "tearing" on an analogue TV, but they were on the right track.
Dennis sized it up. "Try four-bit grayscale," he said. She did, and the image snapped into sharper focus, the tearing less extreme. Effie realized she had it interpreted as a landscape image when it was a portrait and corrected it, and there it was, clear as day. It wasn't a very high-resolution image, but it was large enough, and the contrast sharp enough, that they could clearly make out a girl's face.
Dennis's eyes widened. "Isn't that Becca?" he asked. Effie nodded. "Yeah...and Hiro said the thing went nuts when some girl walked past him...but why would they be looking for her?"
The DOS fairy shook his head. "I don't know, but...we should tell Mikey."
