At the end of the passage was a massive, circular air pressure door with a rotating lock in its center. Huo Shan pressed his palm against an adjacent biometric panel, then underwent a retinal scan as a red dot suddenly lit up.
"Zone 11 employs a three-tiered defense system," he explained as he worked. "The outermost layer is a physical barrier, which includes the alloy walls and laser net you just saw. The middle layer is an Energy Shield, maintained by twelve reactors distributed throughout the base. The innermost layer is the biometric lock—everyone entering the core area must pass genetic verification. You can only enter the zones your identity grants you access to; you can't enter unauthorized areas."
The air pressure door rumbled heavily as it slid open a crack a dozen-or-so centimeters wide. The group filed through into a vast space, like that of a large city built on the surface.
