Thank you for all your help. I am now a lot further. However, I wonder if there is a bug here. I have reached the secret room with the sentence "In the center of it there is a thick sheet of paper on which something has been written."
I can't take, look or read this sheet of paper with any command I have tried though it sounded from the previous "cut scene" that it should be important. So am I supposed to read it or take it somehow? Thanks.