She looked around at them, defiant, defying her own shame. “I …” She sighed and shook her head. “I don’t know … how my brain is …” She sighed again. “I don’t know anything, I guess. I was used. I was controlled, but then, even after you guys …” She made a gesture with her hand, as if she was pulling something out of her head. “I still wanted revenge, and the wiring played into that. I still wanted revenge. I guess I do even now. But yeah, what Mr. Stern told me … There has to be a line.”

Keats saw tears flowing and his heart yearned to touch her, to take her in his arms and protect her. But that felt impossible now.

“I thought of what my dad would say,” Plath said, dejectedly. “My dad, my brother … there still has to be some kind of limit. A line drawn.” She wiped away the tears, then, resolute, said, “So we stop Caligula. But. But we give the gun to the kid.”

Caligula disliked disguise, but he knew how to use it. There were two approaches. You could either become part of the background and therefore be ignored—like a janitor. Or you could pass yourself off more boldly, pretending to be someone in authority, someone who would compel obedience. For example, pretending to be a cop.

And Caligula understood diversion. He’d spent a part of his life working the carnival as a trick shooter and knife thrower, and he’d met his share of magicians. Sleight of hand was all about misdirection: look over there, not over here.

Finally he understood simple brutality.

All three were required to gain access to the subfloors of the Tulip.

He dressed as a janitor, having first determined what the AFGC janitors wore and when they worked and through which entrance they came. He gathered his long gray hair into a bun and pushed it up under a do-rag, slipped into gray-blue overalls, and, crucially, applied just enough dark makeup to be arguably Mexican. In the world as it was, a dark-skinned older man dressed as a janitor was as close to invisible as it was possible to be. It wasn’t just that people didn’t notice you; it was that they actively avoided making eye contact with you or noting any feature.

But timed to coincide with his fraught passage through the security station on the first subfloor, Caligula arranged a distraction in the form of a call to NYPD claiming to have seen a homeless white woman waving a knife and threatening people on the street in front of the Tulip.

The choice of a fictional white woman was important, because it in no way pointed to a theoretically Hispanic janitor. And, as well, there actually was a homeless white woman with a shopping cart on the sidewalk. Five bucks and a secret message from “aliens” in the person of Caligula had ensured her presence.

The police duly came roaring up. The security guards at the entrance duly ran to see what was happening. And the sublevel security guards duly glued themselves to their monitors and muttered jealously about those guys upstairs who at least have something going on.

Caligula dragged a heavy floor cleaner past without notice.

Down the stairs. One level. Two. The door was locked but was easily defeated with a six-inch segment of metal venetian blind.

The temperature went up ten degrees from stairwell to mechanical room. As mechanical rooms went it was a nice one, three stories from grated floor to pipe-crossed ceiling, with catwalks offering access to massive blowers, electrical boxes, alarm systems, and telephone and cable panels.

Everything was color coded, so it was easy to pick out the natural gas pipes from the water lines and cable conduits. Red. An interesting choice, Caligula thought. He might have gone with lilac. He liked lilac.

The first job was to make sure no one was down here. He walked around, looking lost with his floor cleaner until he located the engineer on duty. He was a middle-aged man, staring at an iPad propped in front of the readouts he was meant to be watching.

Caligula gave him a hello wave and a hatchet in the neck, stepping nimbly out of the way of the blood spray.

He squeezed fast-drying epoxy around the edges of the doors. He looked around, spotted a metal table, dragged it over to the door, tipped it on its side, and epoxied it across the door. Once the epoxy had hardened in twenty minutes, it would take a tank to break through. He would leave via the freight elevators, which he’d be able to watch more easily.

The next thing was to eliminate any source of spark. It wouldn’t do to have the gas ignite too soon. He turned off the heating system. He decided to accept the risk of a random spark from one of the electrical panels—unlikely, given the pristine newness of the building.

Then he located the safety shutoffs that would choke off the gas in the event that the computers decided a pipe had ruptured. He jammed that useful piece of equipment with a wrench.

Which left only the last three phases: opening the flow, setting the timer on the igniting explosive, and getting the hell out of the place before it blew up.

About twenty floors above Caligula, Burnofsky worked. The beautiful thing about nanotech, he thought, was the whole nano thing itself. Nano: small. Tiny. Invisible to the human eye.

He could begin growing self-replicating nanobots within full view of the hidden cameras. A million of them looked like a couple of handfuls of dust. Blue dust, in this case, because in a moment of wracking guilt back before—before the new Burnofsky—he had given them the color of his daughter’s eyes. He’d done that as a strange expiation. An homage? Was that the right word?

He was still secretive about drinking the booze. He rolled his wheeled office chair back into a blind spot, poured into an empty soda can, then rolled back into view.