Seeking adventure, young American Simon Bukner joins the British army in war-torn Europe of 1916. During a particularly ferocious battle, Bukner and his battalion are pushed into a series of dark trenches where they encounter mysterious phenomenon. As they move through the labyrinth they discover that there is a greater evil hiding underneath the battle-fields of the Great War — an evil that is forcing its way into our world and threatens to wipe out humanity. In the depths of this newly discovered underworld, Bukner must confront the dark forces and fight for the survival of mankind.