The Silence

by Mark Alpert

  Zia responds to this boast with a grunt transmitted over the radio channel. Then I detect vibrations in the slurry of mud and rock chips packed into the cone. On my sonar, I see Zia open her War-bot’s hands and extend a sharp, flat blade from each of her steel fingers. The blades are six inches long and shaped like garden trowels. They’re ideal for digging.

  Her loudspeakers let out a roar, loud enough to reverberate across the seabed. Then she lifts her massive arms through the sludge, using them like steam shovels to push the mud and rock chips aside. Once her hands are above her turret, she jabs her trowel-like blades into the mud and levers her War-bot upward, lifting her turret above the cone’s rim. Now there’s no steel barrier between her and the Snake-bot, so she can send a radio signal to its antenna.

  I’m reluctant to give Zia advice—she hates it—but I can’t help myself. Make sure you switch your transmitter to the ultra-low-frequency band. A low-frequency signal should be able to pass through thirty feet of bedrock without any trouble.

  Yeah, yeah, I know. I set the frequency all the way down, to less than five hundred hertz. But I’m not getting any response.

  That’s a problem. Although the neuromorphic circuits in the Snake-bots have been deactivated, I thought their radios would still be operating on reserve battery power. But they’re not. Apparently, Sigma didn’t design them that way.

  Okay, it looks like we’ll have to connect to the Snake-bots by fiber-optic cable. There should be a cable port at the Snake-bot’s front end, next to its primary antenna.

  Should be? You’re not sure? Zia’s voice is incredulous. I’m gonna have to punch through thirty feet of rock to get to the front of this Snake-bot. If I don’t see a cable port there, I’m gonna be annoyed.

  To my surprise, Amber comes to my defense. Every Snake-bot we fought had a cable port at its front end. There’s no reason to think this one will be any different.

  Zia broadcasts another dissatisfied grunt. Then she starts clawing at the sludge above her turret. At the same time, Amber and I free our robots from the densely packed mud inside the cone and clamber upward. My acoustic sensor picks up a hissing noise, the sound of high-pressure air rising from the Snake-bot’s horizontal borehole. It sounds like our drill cracked the bedrock just above the borehole, and now the air is leaking into the vertical shaft we dug. It whistles along the outside of the cone and collects in a bubble above the rim, forming an eight-foot-wide air pocket.

  After we climb out of the mud-packed cone, our robots can stand inside the air pocket, which is big enough for the three of us. The sludge in the shaft above us can’t pour down on our machines because of the tremendous pressure of the air bubble. We have a muddy ceiling over our heads and a muddy floor under our footpads, and on all sides is the rocky wall of the shaft above the cone.

  All three of us flex our steel limbs, enjoying the freedom of movement. Then Zia retracts her digging blades and clenches her hands into fists. Tilting her War-bot forward, she delivers a colossal punch to the rock wall.

  The blow shatters the jagged bedrock, flinging mineral chunks and shards in all directions. A moment later, Zia punches the rock wall again. She throws a flurry of punches, one after another, and in half a minute she pounds a big hole in the bedrock, four feet wide and three feet deep. Then she points at the pile of rubble around her footpads and turns her turret toward Amber and me. Well, what are you waiting for? Pick up the debris and clear the hole, so I can keep tunneling.

  My Quarter-bot and Amber’s Jet-bot spring into action and sweep the shards out of the hole. When we’re done, Zia delivers another flurry of punches to the bedrock, pummeling it like a heavyweight boxer demolishing her opponent, which in this case is the oceanic crust of our planet.

  Working together, we dig a tunnel that runs parallel to the Snake-bot and just above it. Now that I’m out of the cone, its steel walls aren’t blocking my sonar anymore, so I can view the Snake-bot directly below us, a steel tube seven hundred feet long. It lies motionless at the end of a borehole that extends thousands of miles to the west. The machine came all the way from Sigma’s factory complex in North Korea, tunneling under the Pacific Ocean so it could attack North America by surprise. But this Snake-bot never made it to America. Neither did the five others, which lie in parallel boreholes a hundred feet farther down.

  When we fought these machines in Yorktown Heights, we called them tentacles because they burst out of the ground and flailed at us, but here below the surface, they look more like monstrous worms. They’re encased in thick armor and filled with powerful motors and neuromorphic circuits. The machines are fifty feet wide in the middle, but their front ends taper to slender tips. In addition to containing the primary antennas and cable ports, the tips are loaded with all kinds of sensors. They also contain the Snake-bot’s drilling bits, which are similar to the ones Amber built but ten times larger.

  I know that Zia sees the Snake-bot on her own sonar, because after a couple of minutes she starts punching in a different direction, aiming her War-bot’s fists a little lower. She’s angling her tunnel toward the Snake-bot’s tip, which curves downward into a deeper layer of bedrock, poking several yards below the rest of the machine. It looks like the Snake-bot was about to change course and tunnel to a lower depth at the moment when I deleted Sigma and deactivated all its machines. In contrast, the tips of the five other Snake-bots point upward. For some reason, Sigma was steering the machines closer to one another.

  At 5:26 a.m., after fifteen minutes of intense digging, Zia tilts her War-bot all the way forward and smashes both her fists against a huge slab of rock in front of her. The slab shatters into a thousand pieces and opens a gap between Zia’s tunnel and the Snake-bot’s borehole below us. Zia approaches the gap, tests the sturdiness of the surrounding bedrock, and then lowers her War-bot into the borehole. Amber and I follow right behind her, scrambling step by step down the rock ledges.

  We land inside a cave at the very end of the borehole, just ahead of the Snake-bot’s tip. The cave is fifty feet wide and full of high-pressure air, mostly nitrogen. Its floor is littered with rock chips and its walls are freshly scarred from the Snake-bot’s drill bits. The front end of the machine looms over us, stretching into the cave from the long, straight section of the borehole and bending downward like the trunk of an enormous metallic elephant.

  The Snake-bot is deactivated, and yet I feel a burst of terror in my circuits. I know what these machines can do. I saw them kill hundreds of people in Manhattan.

  More than a dozen sensors extend from compartments in the Snake-bot’s front end. I spot a sonar device and a large array of cameras, as well as a radar dish and the primary antenna. I also see the Snake-bot’s drill bits, each a giant wheel almost twenty feet across, its rim studded with teeth as big as tusks. But the drill is in its retracted position, with the cutting wheels pulled back from the rock wall and the sensors pushed forward. The Snake-bot wasn’t moving forward when it was deactivated. Apparently, it had stopped digging and started examining the bedrock below and ahead of it.

  I raise my right arm and point at the machine. That’s strange, don’t you think?

  Zia scans the Snake-bot with her own sensors. What’s strange?

  Look at how the Snake-bot’s drill is retracted and its sensors are extended. I think Sigma was using this machine to study something ahead of it. I turn my Quarter-bot around and point at the rock wall that the Snake-bot had pulled back from. Something in that direction.

  It was probably navigating the path ahead. Zia shrugs. You know, measuring the density of the rock layers, so it could adjust its drill to the right speed.

  But I thought the Snake-bots did that kind of navigation automatically while they were burrowing. Why did this one have to stop? I turn to Amber, who’s scanning the Snake-bot too. Don’t you think it’s a little weird?

  I’m worried she’ll say something dismissive, but she nods her Jet-
bot’s head. Yeah, it’s odd. And there’s something else. Turn on your sonar, and take a look at the five Snake-bots below us. Their drills are retracted too. But their sensors are pointing up, not down. I think all the Snake-bots were examining the same thing, one from above and five from below.

  I use my sonar to view the other Snake-bots. Amber’s right. The tips of all the machines point at the same unexcavated area just ahead of their boreholes. I thought Sigma had been maneuvering the Snake-bots closer together, but now it seems the AI had stopped the machines to investigate something. But when I point my own sensors at the area beyond the rock wall, I see nothing unusual. My sonar shows nothing but solid, basaltic rock, no different in density or composition from all the bedrock around it.

  I don’t see anything buried there, do you?

  Amber pauses to check her readings. No, but the Snake-bots’ instruments are bigger and better than ours. They could probably detect things we can’t.

  Another thought occurs to me. Remember what Shannon said about how these Snake-bots were way off course? Because burrowing under the Pacific would take so much longer than following the shortest path between North Korea and New York? Well, this might explain it. Maybe these Snake-bots weren’t headed for New York after all. Maybe this was where Sigma wanted them to go.

  Amber nods again. Yeah, that makes sense. It looks like Sigma was very interested in something buried here. Why else would it send so much machinery to this place? She points at the rock wall, her Jet-bot’s arm paralleling mine. Judging from the angles of the Snake-bots’ tips, I think whatever they were observing is eighty feet to the east and sixty feet below us. Maybe we should do some more digging so we can take a closer look at—

  HEY! Zia interrupts Amber by stamping one of her footpads on the cave’s floor. The ground shivers, and the rock debris bounces and scatters. Are you two looking at the time? It’s after five thirty. We have less than thirty minutes.

  We’re just—

  We can worry later about what Sigma was doing here. Right now, we have to concentrate on transferring our software. If we run into any problems, we won’t have much time to fix them. She strides toward the Snake-bot’s tip and points at a socket below the machine’s primary antenna. Is that the cable port?

  I aim my sensors at the socket, then compare it with all the Snake-bot images stored in my memory files. Yeah, that’s the port.

  Okay, listen up. Zia extends a fiber-optic cable from the mechanical thumb on her right hand. I’m gonna connect to the Snake-bot’s circuits. First I’ll make sure that Sigma didn’t leave any booby traps in the control unit. Then I’ll see if I can restart the machine’s motors and radio.

  I’m not surprised that Zia volunteered to make the first jump. Although we’re all worried about the 6:00 a.m. deadline, I think Zia is the most anxious about the kill switch. It’s not just the fear of deletion that’s bothering her; it’s the fact that her War-bot is helpless against this threat. She hates vulnerability of any kind and despises being inside a robot that’s programmed to erase her. She knows she’ll be safe, though, once she transfers her software to the Snake-bot. The machine has no kill switch because its circuits were built by Sigma. The U.S. Army can’t shut it down.

  Amber raises one of her Jet-bot’s arms. For a moment I think she’s going to challenge Zia and demand to be the first Pioneer to make the transfer. But instead she rests a steel hand on the back of the War-bot’s torso. Once you’re in the control unit, find out how much extra capacity it has. There might be enough room in there for all three of us.

  Zia steps to the side, shrugging off Amber’s hand and moving out of her reach. She doesn’t like to be touched. We won’t have to share circuits. If this works, I’ll turn on the Snake-bot’s drill and dig down to the other machines. Then you can transfer to one of them and Adam can jump to another.

  That’s fine with me too. Amber’s voice is gracious. She doesn’t seem to be offended. Either way is good.

  So glad you approve. Zia telescopes her War-bot’s right arm, extending the mechanical thumb toward the Snake-bot’s cable port. I won’t jump in all at once. First I’ll probe around a little. I’ll radio you if I get into trouble. She inserts her fiber-optic cable into the socket. Better stand aside once I’m in the Snake-bot. If you get in my way, I’ll probably flatten you.

  I have a sudden urge to say something encouraging. My circuits compose five hundred phrases suitable for the occasion, everything from “You got this!” to “You rock, girl!” But they all sound so ridiculous. In the end, I send her one simple message: Good luck, Zia. By the time I transmit it, though, she’s already transferring her software to the Snake-bot.

  Her War-bot stands still. Nothing happens for ten seconds, which is long enough for a Pioneer to explore a whole jungle of circuitry. Finally, Zia sends us an update, but now her signal is coming from the Snake-bot’s primary antenna. She managed to restart the machine’s radio. Okay, I checked out the control unit, and it’s clean. No booby traps. I also turned on the Snake-bot’s sensors, and they don’t show anything but bedrock up ahead. Nothing at all buried there.

  Are you sure? Amber sounds disappointed. Did you check—

  Yeah, yeah, I checked all the instruments. But I did find something that’s a little weird. Adam, you didn’t deactivate this Snake-bot.

  Panic thumps my wires. What? Is Sigma’s software still in those circuits?

  Nah, there’s no sign of the AI. Sigma’s been thoroughly erased from the Snake-bot’s control unit. But there’s a time stamp that marks exactly when the software was deleted. It happened at 11:09 p.m. Universal Time on October 15th.

  I shake my Quarter-bot’s head. No, that can’t be right. We were still fighting Sigma in Manhattan then. I didn’t delete the AI until nine hours later.

  Just listen. Sigma was erased from this Snake-bot—and probably the five other Snake-bots below us—before you erased the AI from the rest of its network. Which means someone else deleted Sigma’s software from this machine.

  Someone else? But who—

  Zia interrupts me with a loud burst of static. At first I think she’s making the radio noise because she’s annoyed with me. I assume she’s disgusted by my failure to grasp her point. But the static keeps blasting from the Snake-bot’s antenna, droning on for more than five seconds, and it occurs to me that maybe Zia isn’t generating the noise. Maybe something inside the Snake-bot is interfering with the radio.

  Zia! Can you hear me? What’s wrong?

  She doesn’t answer, but the static gets louder. Frantic, I turn to Amber. I’ve lost contact with Zia! Can you reach her?

  Amber doesn’t answer me either. Instead, she raises one of her long black arms and silently points at Zia’s War-bot. It’s still connected to the Snake-bot by the fiber-optic cable sticking out of Zia’s thumb, but now the other fingers on her steel hand are twitching. A thin tendril of smoke rises from her elbow joint.

  Then her War-bot explodes.

  Chapter

  21

  The blast flings my Quarter-bot across the cave. My robot hurtles toward the jagged wall of the borehole and smashes against the bedrock.

  I slide to the floor of the cave and come to rest on a pile of rock chips. My sensors stop sending me data. I can’t see anything, and my motors won’t respond to my commands. I feel no pain—all my pressure sensors are offline—but shock and terror careen through my circuits. The impact must’ve broken the primary connection between my control unit and the rest of my Quarter-bot.

  Luckily, my secondary connection still works. I reroute my signals and turn on my cameras and sonar and radio. I pivot my Quarter-bot’s head and wiggle my steel fingers. But the motors in my legs still aren’t responding. I see why when I focus my sensors on them: the blast twisted both legs and mangled their motors. I’m crippled. Even a welding torch couldn’t fix this damage.

  That’s nothin
g, though, compared with the damage to Zia’s War-bot. Her steel hand still hangs from the cable attached to the Snake-bot, but the rest of her machine lies in pieces on the cave’s floor. Her torso is split into two crumpled halves, exposing her control unit, which is cracked and charred. I train my cameras on the unit and gaze in horror at the melted wires that once held Zia’s mind.

  But she was inside the Snake-bot too. I know that because she contacted me using the Snake-bot’s radio. She transferred at least some of her data to the larger machine before the explosion. The machine’s antenna is still spewing static over the airwaves, but maybe Zia is somewhere behind the radio noise, hidden within the Snake-bot’s circuits. There’s a chance she’s still alive.

  My acoustic sensor picks up a grinding noise to my left. I turn my cameras in that direction and see Amber limping toward me. The explosion battered and dented her Jet-bot, but she can still walk. Adam! How bad is your damage? Are you—

  I have to find Zia. I’m going to transfer to the Snake-bot.

  What? Are you nuts?

  She turned on the machine’s radio, which means I can transfer wirelessly. There’s a lot of static, but I think I can—

  My God, I don’t believe this! Didn’t you see what happened to her? She’s gone, erased! And the same thing will happen to you!

  Instead of answering, I load my data into my Quarter-bot’s radio transmitter. Under ordinary circumstances, I would copy all my data and transmit just the copied files—that way, I could occupy both the Snake-bot and my Quarter-bot at the same time—but the intense static swirling between the two machines makes that plan impossible. My only option is to compress my mind into a dense packet of software and look for an opening, a momentary lull in the radio storm.

  The static ricochets across the cave, the radio waves mixing and interfering with one another and building up to deafening amplitudes. But every few milliseconds, the waves cancel each other out and the noise dies down to a low rumble. That’s my opportunity. I wait for the next moment when the radio noise subsides, and then I leap out of my Quarter-bot. My software rockets across the cave and converges on the Snake-bot’s antenna.