Math had never been her strong suit—that was Alex’s forte—but she had grown up with a physicist for a father. He’d insisted they both take calculus in high school, although by that time Sandra had known she was heading for a career in law enforcement. Not much call for math in her field, unless you were a forensics egghead, which she most decidedly wasn’t.
What she wanted most was to make detective and work homicide, but that possibility was many years away. She would have to do her stints on patrol first, learning the ropes and proving herself smart enough—and hard enough—for the job. She’d made the mistake of voicing her goal out loud at the academy, prompting knowing smiles from her teachers. “Everybody thinks that as a cadet,” they said. “Give it a few years on the force, and see if it changes your mind.”
Sandra had no intention of changing her mind. She’d seen murder before, and she knew how it could tear a family apart. She wasn’t some stream-addicted kid high on crime shows. She knew what she was asking for. And she knew she could handle it.
She surveyed the unfamiliar data spread out in front of her. It seemed to be strings of characters—the RFID keys—with geolocation points attached. Many of the keys had now been expanded into their meaning: credit card accounts, membership cards, articles of clothing, phones, entry gates. Even the baseballs, it seemed, had been tagged with RFIDs, presumably so that claims that a certain ball had been hit by a certain player in a certain game could be verified, years later. Most of the data points were connected to people’s names, thousands of them. Most of those people were now dead.
What if she spotted something important in this mountain of names before the experts? Something critical that led to an arrest? That would get her noticed, no matter how young and green she might be.
The first thing to do was to visualize the data. That was easily done; she entered the geolocation points into a globe, and once she zoomed in close enough, she could see the points scattered on the ground like a field of yellow flowers. It was the same basic pattern she had noticed on site, but she was no expert. The distribution meant nothing to her.
Angel had said it was no bomb, but what he really meant was it was no ordinary bomb. Something had caused the stadium to tear itself apart, and no explanation seemed to fit. What she needed was to know where each point—it was easier to think of them as points rather than people—had started in the original stadium. If she could do that, then she could plot connections between where each point started and where it ended up, maybe even find the convergence point for all the vectors and discover where the bomb itself—if that’s what it was—had been hidden.
Sandra thought she knew just how to accomplish that. Each seat, after all, had a number painted on the seat back and armrests. She had access to the police database of eyejack views of the wreckage, and she could easily find a map of the stadium’s seating chart. The hardest part would be searching through the millions of view frames to find all the instances when a police officer saw one of the seat numbers. Fortunately, she had some experience.
She and Alex had been Life Loggers for years, making their eyejack views publicly visible and interacting with viewers. Simply the fact that they were twin teenage American girls had brought them a lot of traffic. It was something they did together, but her sister hadn’t been interested in maintaining the site. Learning the practical skills, like using pattern-match programs to find and mark interesting features in vast quantities of eyejack data, had fallen to Sandra.
She downloaded the latest version of one of her favorites, and initiated a search. Finding the shapes of numbers in video streams was one of the program’s built-in features, so she didn’t even have to go through the process of training it to recognize a particular face or object. In moments, it started spitting out individual frames of the views in which numbers were visible. Since the views were all geo-tagged, she could tell where each number had ended up. And since she had a seating chart, she knew where each number had started.
Before long, vectors began blooming on her display, but they didn’t fit the pattern she’d been expecting. She’d imagined a shape like a porcupine, lines radiating outward from some central point. Instead, she got a mess. The lines were stacked every which way, more like a spilled box of toothpicks than any kind of pattern. She sighed. This was going to be harder than she thought.
Either the programs she was using didn’t operate the way she was expecting, or else each person and object in the stadium had been flung along different lines of force. Which didn’t make any sense at all.
A thought occurred to her: partial numbers. The seat numbers in the stadium had three, four, or five digits. A five-digit number that was partially obscured, or at a bad angle, might be interpreted by the software as a four- or three-digit number. That would contaminate her data. Probably not enough to make it as haphazard as what she was seeing, but perhaps there were other issues as well. Now that she thought about it, there could be other numbers visible, too—numbers from signs, numbers from jerseys, anything other than seats—and that would confuse her results as well.
She posted a question about the problems she had thought of to a few of the discussion boards she used to frequent. The alternative—that she had made some fundamental blunder in setting up the software—was more discouraging. She spent a few minutes looking at example views and verifying the seat numbers, but as far as she could tell, the software was doing what she intended.
Her phone chimed, the sound of an incoming message. It chimed again, and then twice more. It continued to chime erratically, until the sounds came so quickly it sounded like an old-style telephone ring. What on Earth?
She checked and saw that there were answers to her discussion board queries. Thousands of them. That didn’t make any sense; a lot of people used those boards, but not that many. She started browsing the responses, and realized that what she had written revealed the fact that she was investigating the stadium disaster. Of course. Word had spread as rapidly as it always did online, and now she was being bombarded, mostly with well-wishers and conspiracy nuts. She did a keyword search for the program name, and was able to find a few meaningful responses, one of which offered a patch she could use to cull out the false data. Another message was from someone called TheAngelG. The message read: Sandra! I see great minds think alike. Angel.
All the messages made her nervous. She could easily get in trouble for interacting with the public about an ongoing investigation, especially one of this magnitude. What if a reporter found her query and jumped to conclusions, even assumed she was a detective? They’d bury her at a desk filing paperwork for the rest of her career.
She applied the patch and checked her results again. No good. The lines were different, but just as chaotic. Could it be that seats had really been thrown in such random directions, with such different degrees of force?
Something tickled at her brain. The lines were messy, but not entirely chaotic. She thought she could discern, just at the edge of her consciousness, a kind of pattern, some deep part of her brain recognizing something she couldn’t put into words. Or was it merely the human brain’s need to make sense of what it saw, like seeing shapes in the clouds?
She turned off the eyejack display, and her old bedroom sprang back into view. She might not have the mathematics background to identify a pattern, if one existed, but she knew someone who did. She descended the stairs and found her father at the kitchen table with a mug of coffee.