Ian stared at the boundary of space ahead of him. This place is also known as the Veil. This is where humans could enter the Curtained Imperium and be randomly transported to one of the hundreds of marked, dangerous areas. It's also where the dark races from the Curtained Imperium come out once they want to visit the Human World.
The conflict between the Human World and the Curtained Imperium didn't reach the point of irreconcilability. Firstly, the dark races had no interest in the environment of Earth. The Curtained Imperium is only the most conducive environment for Dark Races to live because of the abundance of Yin energy that naturally strengthens the physique and energy concentration, nourishes the cells, and a lot many other benefits.
How about on Earth? The yin energy concentration was quite pitiful. Only a select few cemeteries had decent concentrations, but they still paled in comparison when compared to the Curtained World.