Switched

What is left of the world has been split into the Dark and the Light.
The Dark has your worst fears, the saddest people, and a cruel and selfish Council.
The Light is the opposite. There are smiles, there is laughter, there is light.
Annually, two people must be picked to switch sides. Luci Pangborn of the Dark has never smiled. Alex Citrus has smiled all his life.
Now they must live each other's life. But as they dig deeper into the person they've switched with, they learn secrets. Secrets that, if discovered, could get them killed.