Between the nations of Balor and Biconia lay the Iron Pass, a mountain range that has served as a natural border between the two countries for hundreds of years. But when a long standing land dispute turns into armed conflict, passage through the Iron Pass becomes the only safe way to transport deserters and prisoners. Far from the front lines, the troops that make this journey expect no glory. During a routine prisoner exchange, two enemy squads are ambushed by an ancient horror, cutting them off from their allies. Chased by an evil they do not comprehend, those that remain must navigate the ancients tunnels network connecting running throughout the Iron Pass and work together if they want to survive.