To finish the fire arrow level of securing the bridge faster, when shooting arrows, select a spot for the crosshairs that lets you shoot the arrows that come from different directions. When the Indians jump over the wall, instead of shooting, run around the TNT and kill them with melee attacks. When Quick Killer appears, only shoot when he is right away from the barrels. You are better off just using melee and your flask. Quick Killer is not hard to defeat.