The thing that said it was a man made its visor transparent. Inside, Mother saw … nothing. She extended a camera boom to see inside the suit better. The suit was empty.

“You’re a machine after all,” she said, puzzled. Men can lie. I see that it’s not a man. Machines don’t lie. But, it lied. The puzzle was too hard for her, so she gave it up. At least the machine had shown her what she needed to know. It was not a man from one army pretending to be from another, “living a lie” as Booker had explained. So, it was not a mass killer like the one she’d found in the city. And, now that she’d disarmed it, it seemed harmless.

Mother had work to do. She drove 300 meters down the tunnel, selected a rock fault 7 feet up one wall, and drilled a hole there, packing it with explosives.