Set in 1917, the Great War has been raging for two long years and new recruit Simon Bukner, a US Army soldier, is the latest to face the harsh realities of war. His first mission sees him get lost deep behind enemy lines, alongside his battalion of Allied troops, after trying to break through the German positions and into Allied territory. The Germans attack hard and the Allieds get pushed deeper into enemy trenches until they’re ambushed and gassed.
Bukner manages to escape into an underground safe-house but everything has changed. The dead are rising from their muddy graves and attacking any living creature they can find. Now Bukner must try and escape through the scores of German soldiers, while fighting off flesh-hungry zombies. As Bukner shoots his way through the trenches, he uncovers a truly horrifying plot to create an army of the undead.
But, in a bizarre twist, Bukner discovers that the zombie force is actually being created for the benefit of humanity. A shadowy group of vampires has enlisted the help of a necromancer to make them their own personal army of the walking dead. This unlikely alliance is a final effort for the vampires who are struggling to stop terrible demons from opening up a portal to Hell and wiping out every living thing on Earth.
Now, armed with powerful vampire weapons and a magical artefact called the Shadowhand, Bukner must venture into the bowels of hell and stop the demons once and for all.