yeah nizwiz is right. if you want a very minor walkthrough for this little part, read on.
all you have to do is this: when the level first starts, there should be an arch either in front of you or to your left. walk through it and there should be a square garbage pit on your left. past that, still on your left, is the wall of a building. over to the right, when facing this wall, is a wide, deep chasm and near the edge is a door. go inside (youll be in a bar) and watch the cutscenes. then youll get your weapons back.