You should be coming from the back end of the whole city, so enter the glass city right there. Coming from the left you walk up
2(!) stairs and enter the door to the left there, so that you are walk around on the outside and reappear still in the same room
after that, but farther in the background. Enter the crystal room in front of you that looks like an elevator and ring the glass bell.
You will be transported to the foreground by lightspeed!
Walk around here and approach the crystal clear chalice. Before you can even reach it Master Goodmold of the glassmakers will come and greet you.
He is the master of all glassmakers in Crystalgard. Even though you are not invited he
is very friendly and explains a lot of the happenings in and about Crystalgard to you.
After talking to him beam back into the background and leave the room through the last remaining door in the midground of this room, the door to the right.
You will now sneakily listen in to an interesting conversation between Master Crucible and Bishop
Mandible. They are talking about a sphere to look into the future. Now that is a nice invention.
Leave this place through the front door in the upper middle of the screen and when you are finally outside
look up to the workers on the tower.
Cast the invisible spell on them and enter Crystalgard again to where you
just came from. Now you can enter the first crystal here and beam you up to
the workers by ringing the glass bell, and they won't see you as you are invisible to them. Examine the blade
they polish and you will uncover the pattern for sharpening
Pass by the workers and use the other beam crystal to get down one floor.
Now you can have a look at the future sphere and see how to easily impress the
shepherds. Of course, note down that spell! Why the shepherds are so afraid of you is what you will find out in the near future, so go on.
You can have two more short looks into the future before the spell is hearable
again, but the other views won't spoil anything for you.