This will show up early enough in the novel, along with some other hints, to put readers on notice that the stakes for the characters are higher than they seem based on their everyday lives.
The first time Solomon had what he came to call “the dream,” he was frightened, but not deeply disturbed. The one room school house with its rough-hewn, solid walls, slates and sturdy benches was indeed gone, but this was a dream. He was standing in the middle of a clear, hollow crystal with rainbows playing across its facets. He could see large purple trees outside and hear a perfect C-sharp chiming every minute or so, followed by a rumbling B-flat.
Even this morning when he woke up yet again from that dream, he could hear the regular cacophony of ravens, loons, owls and geese, smell the horse dung and see the red apples on the tree outside the window. But as he walked the short path from his cottage to the school, he felt uneasy – the shadows seemed different – wrong for a September day. He looked to the eastern sky and saw what he expected, a normal sun beginning its lowered arc across the south to the west.
As he turned to walk north, however, his eye was drawn to a fainter, but still definite sun fairly high in the north sky, disappearing behind clouds then emerging, this time even higher and brighter, and no one going about their early chores appearing to notice anything amiss.