"Ohhh," she purred, as they came to the alley behind the building. "The granddaddy of transmitters," she assured him, pointing her sonic at the door knob she'd come to find, then turning it. It was dark inside, but there was a humming. She pressed a finger to her lips, then pulled him inside with her and slid her back against the wall.
Hum. Hummm. Hummmmmm. Right. That sounded like an engine, though it could've just been any old mechanical sound - a bunch of computers whirring... But if it were an engine, a true engine, then this was a...
"Oooh," she whispered. "Ohhh, that is good. Looks just like a warehouse, right? Only it isn't! As soon as they're done here, just woosh, off they go again, no muss no fuss, a'right?"
She'd already triangulated the primary power source, and so off she went, turning and twisting down a corridor that looked very much like a hallway. She squinted, wondering just how deeply the illusion went. Usually, it was only on the outside, but no, no, this was intricate!
"What are they doing here?" she asked John Smith, as she threw open another door. And there it was at last - this must be the command center. The room was empty, but the walls themselves were covered with lights and wires and buttons and -- she threw herself into it, pulling out wires here, reconnecting them there, putting on her spectacles and squinting at a particular set of glowy rods that pistoned up and down.
"No," she said, turning her head upside down and squinting at the device. "No, but that would mean -- noooo -- they're just fuel! That's all, the human race, all those neurons, the chemicals in your brains just churning away, and welllllll, why not just have them all walk right in and -- Oh, no you don't!" She wrapped her palm around the pulsing green bar and pulled -- hard. It came free, and with it an answering klaxon. The room flooded with red light, and she shouted, "Ah-ha! Now I've got your attention, don't I?"
She threw the rod at John Smith and tore out of the room, expecting him to come.
There would be stairs, stairs, staaaairrssssahhh-haa! And up she went, until she found what was supposedly the roof. She burst onto it, then raced to the edge and looked down. Sure enough, a drove of humans were converging on the warehouse.