I assumed that you would have no difficulty with 5a. in particular, Prospero.
I have a full grid, but I can't see part of 17d. I have the answer and I think, 'teachers' with 1 unclued letter, but not the rest.
Well I have sixteen letters, all beautifully symmetrical in the grid, and internally checksummed - and I can see they lead to a four letter word - but not particularly magically, though the first post suggests there’s something else there...
You know the bit in Inception at the beginning when an ancient Saito meets a half drowned Leonardo in his castle, and remembers something as if in a long forgotten dream?