Prologue: Sand Siblings

Most could see them as business partners, that nothing would spark between them. Some see them as normal people who'd go out as 'friends'. What people physically see about them was enough, but they actually don't have the slightest idea of the events that occur when the lights are off, or if they are off their sights. What do they do when they see each other in the middle of the bridge leading to their respective villages? What happens when no one is looking at them? What happens when they are alone with each other? What happens when they are trapped in their own world?

No one knows but them.