BlackSite: Area 51

It was supposed to be a routine mission three years ago. Enter a bunker deep inside Iraq-territory, retrieve a chemical weapon and get out. But inside the complex was no chemical weapon. Instead you encounter mutated humans and other strange creatures. With one man down you escape that hell and move on. Now you are called to Nevada because something terrible happened there (see Area-51) and it affected the nearby city. But you soon realize, that all this has something to do with what you encount...