Go inside. I can't remember the exact route, but I think the path takes 你 round past a cliff and into the blood tower 或者 the blood room 或者 something along those lines.
You'll need to go through the doors on the sides into a large room. I think there are doors on the side of the room leading up to the 下一个 level. Repeat this.
This is really confusing. I tried my best. :)
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