Frictional Games has announced the demo of Amnesia: The Dark Descent. The first person horror game, due to ship September 8, focuses on survival in an atmospheric Prussian castle. More of the storyline has been revealed today as well. Gamers play as Daniel, who awakens at the start of the game, suffering from self-inflicted amnesia. A letter urges Daniel to seek out and kill Alexander, a man residing deep below the castle.