Null Set

by S. L. Huang

My hands tightened on the pieces. I had to be able to do this. This was my superpower. My realm.

  Except that I was a mathematician, not an engineer.

  I’d even given in and emailed Checker a copy of the specs in the middle of the night, but morning had rolled around without a reply from him, which was … unusual. Very unusual. His responses tended to be improbably instantaneous.

  I half wondered if he was ignoring me. Maybe it was comeuppance for me ignoring him for so long and then contradicting him during an operation. That didn’t seem like him, but what did I know?

  I pushed the gutted hardware aside and picked up the specs again. The logical pathways were so clear to me, including their loops and redundancies. I should be able to condense it all. I could condense it all, theoretically, but the theory wasn’t good enough. What I wanted to do was possible according to the laws of physics, but the necessary knowledge of circuits and wires just wasn’t in my head—hell, the components I’d need might not even exist, for all I knew about electronics.

  A skinny black girl handed me a box the size of a cigarette pack, circuits and wires splaying out the sides.

  “What does it do?”

  Laughter from her, with a savage edge. “Go find out.”

  I tried to shake off the apparition; it clung for a moment before fading back into nothingness. Christ. I needed to figure out some way to make this stop.

  Fortunately, just then my phone buzzed, distracting me. Finally.

  NOT A HWARE GUY, Checker’s text said with uncharacteristic terseness—yeah, he must still be mad. CAN ASK ARND IF U WANT.

  Damn. Checker was good enough at basic hardware that I tended to forget he identified way more on the bits-and-bytes side of things. And I wasn’t keen on involving someone else.

  I tossed my phone in my hand, frustration burning through me.

  Wait. Wait.

  My whole focus went to the mobile phone in my hand. I examined it closely, then got up, walked over to the wall, and smashed it against the corner. The case broke open neatly along the seams.

  I looked back to the pieces of the Arkacite device strewn on the floor. A massive jumble of circuitry, hiding the simplicity of what it did. Arkacite had used it to deal with the design problem in a language they understood—but I didn’t need their language if I could translate it into mine.

  The heart of the hardware was simple. All I needed was the ability to send signals—a lot of signals. The Arkacite device had ponderous engineering in place for the directionality and calibration problems they’d been trying to counter, but I didn’t need any of that—if I had enough point sources in my grid.

  A dense enough net, with every device able to reach out and sense the position of every other one … a net that was able to adjust itself according to what it found, according to its place in time and space … and all that was left was math.

  Not programming or hardware. Just math.

  I gazed down at the split-open cell phone for another few seconds, then laid out its guts next to the pieces of the Arkacite device and pulled over some old academic journals to scribble on the backs. If I cut all the inputs to a subliminal audio frequency and then fed in the density of smartphones in Los Angeles … almost everyone had smartphones these days, even homeless folks, or kids lacking any good support like Katrina and her friend. Pseudocode spiraled out from my pen, structuring the logic my app would need. GPS variables, density of other phones as a proxy to population … raise or lower the signals instantly, according to a hair trigger … I sat and wrote, sprawled and wrote, wrote and wrote and wrote. The algorithm was mathematically complex enough Arkacite never would have jigsawed it together from their testing data, but it would be beautifully simple from a coding point of view.

  I hoped.

  Shit. I scrawled a box at the end of the completed program outline and sat back on my heels. Now I didn’t need a hardware guy, I needed a software one—someone who could transform my mathematical outline into actual programming and then, well, package it into an app, or whatever software engineers did.

  I needed Checker. As I’d known I would, in some fashion. I needed to give him all this and discuss it with him and ask what he needed to make it happen, which meant I had to go to the Hole, where I was going to get an earful of a lecture about the night before.

  It was midafternoon. I put my phone together and checked in with Arthur via text rather than calling so he couldn’t gnaw at me with questions about Simon—I had no illusions about Checker keeping the previous night’s incident to himself. Then I grabbed my stack of pseudocode and reluctantly drove back to Van Nuys. I was fully braced for Checker to lay into me immediately about stupid risks, possibly mixed in with a scolding about not telling Pilar what had gone down, and for me to sit there and deliberately not tell him it was worse than he knew.

  Instead, he jerked around when I came into his computer cave as if he hadn’t already seen me coming on his security cameras.

  “Cas,” he said, his hands slipping and dropping the tablet he’d been holding. It clattered to the floor, but he didn’t seem to notice. “Hey. Hey.”

  “Uh, hi,” I said, thrown. “I have a plan. Can you build a smartphone app out of this?” I tossed the sheaf of pseudocode on his keyboard.

  I was expecting more objections to the brain entrainment, but instead he just pushed up his glasses and started reading. “This doesn’t look too bad, actually. Is it—um. You figured out how to use cell phones for it.”

  It wasn’t really a question, but I answered anyway. “I did. Brilliant, huh? Los Angeles has so many phones; I can lose all the other junk the Signet Devices needed. This can run in secret on everyone’s smartphones—everyone’s, everyone who has one—and it’ll adjust in real time according to the algorithm and blanket the whole city. Keep everybody safe and calm.”

  He twitched at that, and I waited for him to protest again, but he didn’t. He also wasn’t looking at me.

  The silence stretched out.

  “I’ll start working on it,” Checker said, still avoiding my gaze. “How, um. How are you going to get this onto the phones?”

  “I need some way to hack the cell network. I figured you were the one to ask about that.”

  He seemed to get some of his sarcastic vigor back then. “You know, usually when people use the word ‘hack’ they’re way oversimplifying. Sadly, in the case of our cellular network, these days it actually is that easy.”

  “Really? How?”

  “You want something that will eventually reach almost the whole LA population? Probably the best way would be baseband hacking—hitting the phone radio processors with a fake tower signal. This used to be a lot harder, but now it’s as simple as buying some hotspot boxes and reconfiguring them. Still, in order to make it remotely feasible to engage a critical density of cell phones, you’ll have to set a lot of the things—I’ll get you all the numbers, but you’ll have to figure out for yourself if you can place enough of them to reach download saturation as people’s phones move in and out of range.”

  “Sounds good,” I said. “What is the range?”

  “About two hundred meters, if I remember right?”

  The estimates slotted in for me lightning fast. I wouldn’t be able to cover close to all of LA, but I wouldn’t have to. I just needed enough high-population areas. Heavily used freeway interchanges, where people would be sitting in traffic while their phones downloaded my program … the canyon roads, the airport …

  “Doing this sort of thing is highly illegal, of course, but it’s ridiculously straightforward,” Checker continued. “It’s the same tech the government uses for StingRay surveillance—did you know the LAPD alone has used that to spy on hundreds of citizens, all without a warrant? Anyway, we’ll have to think about power consumption, but I’m guessing what with you being you, that’s not going to be a huge stumbling block to steal. Depending on how many you want, we can probably rig them for you in a weekend.”

  “Cool,” I said. �
��Thanks. Sounds perfect.” It was, in fact, exactly what I needed.

  But Checker was neither celebrating such an elegant solution with me nor arguing with me about why I shouldn’t do it.

  We had fallen into an awkward stillness again. I didn’t know what to think. When Checker fought with me, he fought: he was loud and blunt and opinionated.

  Not this stilted, muted interaction.

  “What happened with Simon?” I said, when the silence had become too uncomfortable. “Did you track him on the cameras after I left?” I didn’t want to invite a lecture, but I did want to know—and Checker was acting way too strange for my tastes.

  Was this the sort of thing Rio had noticed in me, after Dawna had influenced me? Could Simon have gotten to Checker in a way I was able to notice? Rio had turned out to be immune to telepathic influence, though.…

  “What?” Checker straightened and became a little more animated again. “Right. Simon. Right. Uh, it’s totally weird. He didn’t appear on any cameras at all after I saw him with you.”

  “That’s impossible,” I said.

  “I know. When you left him, it was dark where he was. I watched for the rest of the night for him to pop up elsewhere, but nothing. Then once the sun rose, I checked everywhere. He wasn’t on any of the cameras at all.”

  “Impossible,” I said again. “Those things covered the whole property.” The security map rose in my mind’s eye, the cameras’ fields of view overlapping.

  “I know,” Checker said. “But then I thought, well—he didn’t know you’d directed me to cover his exit. We assumed he’d sneak out and maybe modify the guard’s memory or whatever, but … he didn’t know he wasn’t on the monitors.”

  “So? Why would he care either way if he was?” It hadn’t been his heist to protect, and the man had superpowers, so it wasn’t like he would’ve gone down for the crime by accident.

  “Maybe he just wanted to avoid questions? I don’t know. But if he can make himself unnoticeable—Cas, what if that’s what he did after you left him? Just made himself unnoticeable?”

  “They’re cameras,” I said. “He can’t impact cameras. It’s human psychology these guys are experts in.”

  “And I think he’s on the cameras,” Checker said. “I think he’s on the cameras and I can’t see him.”

  My gut went leaden.

  “Run some sort of program or something that recognizes humans,” I said. “Have the computer analyze the footage.”

  “You think I didn’t try that? I get three results, since I scrubbed you. And when I try to bring them up, I get Pilar, the guard, and an empty hallway. Cas, I don’t think he’s tricking the computer; I think whatever he’s doing is tricking anybody who looks at the footage before we can see him. You told Arthur he kept going on about permission, right? What if he didn’t want to alter the guard’s memory directly, and this was his way of taking care of both the guard and the cameras?”

  “This is altering us directly,” I said. “I don’t buy that ‘not an exact science’ bullshit—he just brainwashed the guard and you and me!”

  “I don’t claim to know how it works,” Checker said. “I’m just telling you what I know, okay?”

  He trailed off. The room got quiet again.

  Checker never got quiet.

  “What is wrong with you?” I said.

  “What? Nothing!” He moved his hand so fast one of his keyboards banged.

  “Okay,” I answered, chewing the word slowly. “Okay. So you’ll get everything we need for the cell phone hacking for me? And translate my program into computer-speak?”

  “Yeah, uh. Sure.”

  More silence.

  “So, what annoying past-life questions are you going to pester me with today?” I tried, as a last resort.

  “Oh. Right,” he said. “Um, none. I mean, I’m not. Take the day off.”

  “You’re not? You’ve been prodding and prying every chance you get and now you’ve got nothing? That’s a nice change.”

  “Cas,” Checker said. He was looking down at the keyboard now, but didn’t seem to see it. “I—I think I made a mistake. You told me to respect your wishes on this, and I just kept pushing, and—I think that was, was wrong of me. So if you still want me to, I’ll drop it.”

  Of course I wanted him to. I opened my mouth to say so.

  His hands were shaking. Checker’s hands were shaking.

  “Holy crap,” I said, everything about his odd behavior collapsing to a conclusion at once. “What did you find?”

  “What? Nothing!”

  “Bullshit. What did you find?”

  He looked me square in the eyes. “I swear to you, I didn’t find anything.”

  The man was a fucking asshole. He wouldn’t stop looking into my past no matter how much I asked him to, and now he was suggesting we drop it when I knew he was lying to me?

  I thought about letting it go. I wanted to. But the way he was acting … if I was in danger, or if he was in danger for looking into this—It would serve him right, some part of me thought. But it was only a small part.

  “Checker,” I said, and I hoped I was the only one who heard the slight tremor. “So help me God, if you don’t tell me what you found out, I will start shooting up the Hole.” I drew my Colt and pointed it at the nearest computer tower. “Now what. The hell. Is going on?”

  Checker paled. “You wouldn’t.”

  “Watch me,” I said. I carried in condition zero and the gun was ready to fire, but I lowered the hammer and recocked it for dramatic effect.

  “Hey, whoa!” cried Checker. “I want to tell you; I do! I—I still might. The reason I didn’t—I’m scared, okay? I’m not like you.”

  I brought the gun back down. “What are you talking about?”

  “I—I can’t say.”

  “If you came across something dangerous, we can deal with it.”

  I spoke more confidently than I felt. But if I didn’t know what we were up against, then I definitely couldn’t protect against it.…

  Checker sniffed loudly and turned away. He wasn’t just scared. He was terrified. Holy fuck. “No, that isn’t— I told you, I didn’t find anything. I was telling the truth. It isn’t just me, either. I don’t know what’s going to happen if I tell you. I don’t. To anyone.”

  “Hey. Whatever happened, whoever scared you this badly, we can figure it out.” My mouth was dry. I wasn’t sure if I was saying it more to convince him or myself. “We can. I promise. I’m very good at finding people and rendering them impotent, and so is Arthur, and so is Rio—”

  Checker choked.

  “Come on, I know you don’t like Rio, but this is the exact kind of situation he’s good in. If there’s someone who’s a threat to us, I can think of no better—”

  Checker’s whole posture had knotted up as if he were about to have a seizure.

  “Oh my God,” I said. All my senses contracted and hardened. The room went flat and unreal.

  “Cas—”

  I couldn’t string thoughts together. Logic scattered like dry leaves. “Tell me you’re kidding,” I said. “Christ almighty, tell me you’re kidding! Tell me it was someone else!”

  “I didn’t say anything!” Checker shrieked.

  Fuck, he’d told me he was going to call Rio— “No. No. I refuse to believe this. You must have misinterpreted. Rio doesn’t come after people like you. He doesn’t. He can’t. He wouldn’t. You’re—you’re lying, or you imagined it, or—”

  “If it makes you feel better,” Checker said in a strangled voice, “I think he’s trying to protect you.”

  “Protect me from what?”

  “I don’t know!”

  “I’m perfectly capable of protecting myself!”

  “I know that!”

  We both stared at somewhere that wasn’t each other. Checker sniffed hard again, and knocked over a few things on his desktop to find a pack of tissues.

  “Cas,” he said hoarsely, “I’m really, really scared r
ight now.”

  “He won’t come after you,” I said again, wondering why the words felt hollow. “He won’t. He doesn’t do that.”

  “He told me he would.” His voice cracked. “I don’t know why you trust him the way you do, but he said—” His mouth worked.

  “What did he say?”

  “He said he was going to destroy everything I held dear and then—and then kill me, he said it—Cas, he was serious, and I don’t know if he meant Arthur, or—”

  I pulled out my phone. My hands were stiff.

  “What are you— Are you crazy? You can’t call him! Tell me you’re not calling him!”

  “I’m going to get to the bottom of this,” I said. I had to. I had to.

  “If he finds out I told you—that’s what he was threatening me about! To keep you from knowing! If he finds out I told you what he said, he is going to kill me, do you understand? And—”

  I closed my eyes. “Checker. I promise. I will not let anything happen to you.”

  “He could do it in a way that you don’t know it’s him! Do you understand what I’m saying? Please, please, please, if you have any regard for me whatsoever, please do not call him, and do not tell him I told you any of this!”

  I curled my fingers around the phone. “Why did he threaten you in the first place?”

  “To stop me from looking into your past,” said Checker quietly. “He knows something for sure.”

  Rio knew something. About me.

  “Cas,” said Checker. “Whatever he knows, he thinks it’s best if we don’t find it. I think he’s trying to protect you. Maybe—uh, maybe we should let him.”

  “What happened to ‘knowing is always better than not knowing’?”

  “Maybe there are exceptions.”

  Rio wanted to keep me in the dark. With Simon stalking me, and voices in my head, and notes in graveyards and Rio threatening Checker and my whole fucking past hurtling forward to crush me. He didn’t want me to know.

  Which felt … just fucking fine with me, because I didn’t want to know. Since all this had started, every fiber in my being had been screaming about how much I didn’t want to. I wanted to run. I wanted to push away, and forget, and take the helm of my own destiny. Bury everything else if I had to give myself a head injury to do it.