Awersome! That was actually the riddle we were most afraid people would not "understand". Would you say, that it takes too much time or is unclear?
We will make this more clear in our next update, as many didnt seem to find the connection there.
In the shelf with the books there is a picture on the wall which shows different medical items of different height. You must adjust the books with the right topic on that height and then put the symbols in order of the items on the picture from top to down at the safe.
