During Chapter 9, you will come across a big wheel with some crosses on it. After getting a "hand" from a bony friend, you can bring the bucket from the wheel to the waters below to fill it, then hand it to Sam who will put it back in the wheel, allowing you to actually start this puzzle.
Let's start by pointing out that the puzzle configuration you get is completely random and the solution in the video above might not be the same for you. However, it is solved in the same manner no matter what, with the first goal being to move the bucket to the very top. After this, you simply need to move the crosses to their correct spots, with the white cross going into the light on the left, the big cross going in the middle and the black one on the right. Once you do this, go and pull the lever where you got the skeletal arm to continue.
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