Not What It Seems

Shade has no idea that she is interacting with the dark spirits of the night, and neither do the others. They think they are playing a fun game with each other...but soon some of them realize that the game is starting to turn deadly and feel themselves starting to get pulled into the spirit world but they find themselves unable to stop playing the game. Why is this? Are they possessed? or just simply addicted to the thrill of the game and unable to stop.