In Silas' dream, as he attempts to head downwards, the lines become more intense, loud sounds akin to screaming echo all throughout the dream, he eventually reaches a point where the lines coalesce into a massive indeterminate structure of some kind. Just looking at the structure causes Silas to feel overwhelmed.
The path downwards is where the sound is most intense, with Jack following it down, he finds himself in a twisting series of tunnels, Jack feels a sense of unease as he wanders about, eventually he finds a crossroads, a path leading forward, left and right, the hum is equally powerful from each direction. The air in these tunnels feels unusual somehow.
The city hums back at Dies again, almost as if it was trying to speak to her, though had no means to truly do so, the sense of unease intensifies as she hums at the city.
In Harinder's dream, the patterns are hard to make sense of, but Harinder understands that a grave mistake was made here in this city that lead to a great degree of suffering for many people.
In Alexander's dream, the lines move towards one central position, coalescing into something akin to a distorted hexagon, seeing this hexagonal thing makes Alexander extremely uneasy.
