When night falls, we find peace in the knowledge that daytime will return soon, and vice versa. But what if the world was split: daytime and night are two different, coexistent worlds, each with it's own laws and rules. At dawn and sunset, our soul switches to inhabit our other being, our 'twin'.
A certain patch of forest is well known for causing anyone who ventures into it to suddenly go blind. Once they leave the area their vision returns. Rumors of treasure hidden within.