In NecroVision you were an American who had joined to fight the Germans in the British Army - that was before you found out about the demons and vampires lurking underneath the Western Front.
All things considered what seemed bad enough - trench warfare, going over the top, being shelled and shot at, got a whole lot worse than you could ever have imagined... In Lost Company - the prequel you get to see life from the other side, as in as a Soldat German.
The thing is that the dark forces that have been unleashed as a consequence of the Allies and the Germans fighting cannot be defeated just by the Germans, British or French. Nope, so much like the legendary game of football, these mortal enemies are going to have to get along to overcome!