The vortex rips through the thick reinforced concrete wall that surrounds the neighborhood like it was tissue paper. Before I can react at all, it shreds its way right through the first house in its path, barely slowing as it makes a bus-sized hole through stone, wood, and brick. It’s moving fast, and it’s coming this way. We only have a minute or two before it arrives.

“Panic room!” I shout to my family gathering down the hall in the dining room. “Now!”

Gramps reacts with reflexes that would have done a much younger man proud. He grips Grammy’s hand and leads her and the girls down the hallway at a sprint. Alan had looked at me like I was crazy when I required this feature in the house he picked for them. I know that even several centimeters of vault-grade steel won’t stop what’s coming, but it will slow it enough that I have a chance to deal with the situation without needing to divert my attention to keep them safe.

I feel Evan on the outside of the panic room door, his bots pulled in thick around him. I bolt in his direction and send him a quick message across our link asking for cover. I get to him just before the wave of destruction crashes through the wall of the house. I ignore the cutting edge of the cyclone, trusting Evan to keep a shield up that will keep the shrapnel suddenly flying through the air from ripping us apart.

I focus on finding the control signal guiding the thing. My bot vision’s overlay shows a chain of bots maintaining a mesh network leading back the way the vortex had come from. In less time than it would have taken me to blink, my electronic mind calculates the amount of the chain I need to take out to disrupt the network.

With surgical precision, I take out the bots along the chain, ignoring the barrage of metal that Evan is keeping just centimeters from my skin. I hit the threshold that my implant calculated, expecting the assault to stop as the control signal disappears, but the cyclone continues unabated. The drywall covering the steel of the panic room walls strips away, revealing bare metal. I hear creaking as the roof above us threatens to collapse. I continue snipping back the chain of bots leading off towards the outer wall of the community. The gap is several times the distance that the bots could maintain their connection.

How is that thing still getting a signal?

I scan through alternate frequencies, check every possible way the bots might be communicating back to their owner.

Then I realize. These nanobots aren’t getting a signal anymore. The vortex of chaos isn’t following the rules of bots as I know them. Absent the control signal, the bots should have collapsed into inaction and begun the countdown to self-lobotomy. Jeff, and it could only be Jeff, has violated the fundamental rules laid out in the Butler Treaty. This swirling embodiment of Jeff’s rage has a mind of its own and is running without any human holding its leash anymore.

“I’m down by half, brother,” Evan cries out. “Whatever you’re doing, do it fast!”

I look closer at the swirling vortex, enabling every overlay the implant can provide, trying to wrap my mind around the patterns of the moving parts. The whipping edges are moving too fast, there is no way I can target them. How did he get them going at those speeds? It’s way beyond the maximum velocity that I could push my bots to. There. A vertical series of clusters near the center connect the whipping outer edges with flexible chains a single bot thick. Thinking it through, the cyclone is like a stack of spinning wagon wheels, the wires forming the spokes of each wheel. The frenzied scouring of the outer edge is enabled by the momentum of the bots whipping around in circles, accelerating all the way around at every point along the spoke. The force of the bots pushing near the center allow the ones at the rim to reach tremendous velocities.

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How to deal with that?

With the control signal disconnected, the processing power those clusters have available to adapt to disruptions has got to be very limited. They should only have the computing resources that the simple onboard processors of the bots provide. They’re fast and dangerous, but they’ve got to be dumb.

I slide in tendrils of bots from below the body of the cyclone, perpendicular to the cutting edges. Targeting one of the clusters, I push on it, applying asymmetrical pressure. I feel the pinpricks of my bots nearest the cluster being destroyed by the whipping bot wires, but I get the wobble that I need. The torque causes the microscopic wires made of bots to entangle with the wires of the wheel above it, slowing the rotation of both. That gives me an opening. I jam as many bots into the cluster as I can and twist hard, turning the lowest flexible wheel into a full collision with the rest of the stack.

If Jeff had still been in control of the thing, he could have easily made adjustments, breaking and reforming the wires as needed, but the AI of the bots is on its own and lacks any imagination or instincts to cope with the disruption. The frenzied beating on Evan’s shield subsides as the cyclone destabilizes. I slice up and through the core of the and sever the links holding together each spoke. The bots that had formed the vortex scatter, whipping through the remains of the house. They burrow into the remnants of the walls, floors, and ceiling wherever they land.

Evan breathes out heavily and wipes the flowing sweat from his forehead with his sleeve. He looks like he’s just run a marathon. “That was too close, Noah. What the hell was that thing?”

“Something Jeff thought up.” I step forward toward the space in the wall where the core of the metal tornado had ripped through. “I imagine he had plenty of time to come up with designs while he was locked up, and he’s obviously had enough time to code them since he got out.”

I survey the wreckage. The overlays are all still enabled, so my field of vision is clouded with swarms of numbers and colors. Oddly, the scattered bots embedded around the place still haven’t shut down. I walk over to one of the walls and take a closer look. A chill breeze makes the hair on my arms stand up.

The bots in the wall start to replicate.

Shit.

Shit, shit, shit!

Jeff has disabled all the safeguards. Those things are breaking the most fundamental rule of nanobot safety: never let them grow on their own. That kind of thing could result in an exponentially growing mass that could never be stopped until it consumed the entire world. It’s exactly the kind of thing that had most terrified Jeff and everyone else who understands the technology.

“Clean up, now! They’re growing!” I call to Evan.

I start replicating my own cloud, working to both starve Jeff’s rogue bots of materials and energy and to make sure that my cloud continues to overwhelmingly outnumber them. I focus the rest of my bots on finding and destroying every single remnant of Jeff’s assault. Evan does the same. I desperately want to rush off after Jeff. He couldn’t be more than a few kilometers from here. This is the only chance I’ve had since the attack on campus to find him. But the possibility of a Gray Goo event isn’t something I can ignore or defer. I scrub and destroy, check and double check, making sure that not a single bot is left loose.

Finally, half an hour and one completely destroyed house later, we get the last growing clump of Jeff’s bots cleared out and destroyed.