ESU leader, Thomas Holmes, stood by his side, in an all-black combat outfit, bristling with holstered and shoulder-slung weapons and communications gear. “That door looks like something off a fucking submarine,” Holmes said. It did. That was exactly what it looked like. It had the same kind of airtight and watertight, hermetic seal and locking wheel, and a six-inch-thick porthole window. The rest of it they had been denied access to. From the far side of the crime-scene tape, Nathaniel could see through the open door that the floor was made up of metal plates. They were smooth and looked shiny. He could also see the inside of a matching door at the other end of the chamber. NYPD bomb techs in their padded suits and helmets were the only ones who’d entered it. They could find no evidence of explosives, and there was residual radiation that had no apparent source of origin.