From Earth (hl2 mod in beta) walkthrough chapter 3 part 4 no kills
Sorry for the german text, now you have to deal with two alien-languages. Not a good walkthrough I know, it is my first one but there are no other walkthrougts for this mod/game, so i decided to create one. From Earth is a free to play mod for half life on steam http://store.steampowered.com/app/334370