Through the Threshold Gap

I slid prone across the cool ceramic entryway, aligning my armor with the low gap under the front door. Keeping my cannon arm flush against my side, I pulled forward on my elbows, clearing the flexible rubber sweep with a quiet scuff. On the outside corridor carpet, the air tasted distinctly of open concrete and hallway drafts. Ahead, the long hall stretched toward a glowing exit sign. Near the wall baseboard, an abandoned plastic keycard tag lay flat on the industrial weave. I tapped its glossy surface with my boot tip to test its stability. It held firmly. I stood upright, adjusting my stance to mark my first official perimeter post beyond the apartment.