If you let the stream obstruction build back up, do you have to complete the other puzzles again??

I am new to the game and the forum. The debris is cleared but what is the keystone? The waterfall stoped running.

Read the earlier posts in this thread. There are several about the keystone.

Ifound nothing about the keystone. I went through all the posts. Can you not just tell me?

Try reading this post and the ones following.

I have tried taking a master builder and a master scientist to the rock and it keeps telling me that it requires calculations. Anyone know what I am missing?

An Adept is enough but he/she must be adept in the both skills: Scientist and Builder!!

how can i do calculations? to move the rock?

Artur, see the post above yours (Laurence's).

Arnie, you could actually give a little more of a clue without giving everything away. You wrote, clearly enough: Nevertheless, my problem was that I read that and translated it to That's not exactly what you wrote.