The walls were built to protect humanity.
But somewhere along the way, they became cages.
Captain Daniel Foster has spent his life defending Sector 4 — a crumbling outer fortress standing between civilization and the unknown beyond. As resources vanish, the walls decay, and command quietly abandons those on the front line, strange tremors begin rising beneath the city.
Then the breaches start.
What emerges from the darkness isn’t mindless. It watches. Learns. Waits.
With his squad trapped in a sector marked for sacrifice, Daniel must decide whether to obey the system that abandoned them… or fight for survival against an enemy that may understand the fortress better than its creators.
In a world built on walls, the greatest danger may already be inside.