Mission 10: The Wolf's Den
After a mid-mission cutscene, you will be in some tunnels and mines. You'll eventually make it to a wooden area with ladders. You need to climb up the area as it is set on fire. As you climb the ladders, enemies will try to attack you so be sure to just kill them while you are on the ladders. This is cumulative, so you don't need to do this on the same ladder and can even continue after dying or restarting.
Here is a video guide with English commentary!
Here is a playlist of guides for this game!https://www.youtube.com/playlist?list=PL-HeW6XkKdULFuRNxPEYw...