in I think second level, when in room with sarge after cutscene with black out and prohphet speaking, kill people and sarge will shoot you with some wepaion, and then eventually come down, but becarful, 1 hit kill, if you shoot him a lot or a hed shot, he fall down and a drop weapon, but then get back up and grab nearest weapon. enjoy, sorry bad spellung, lazy! P.S. he is deadly with carbine
