The game's heroine, Karina, is a young girl from an underground city who doesn't know what sunlight is. She works as a trainee librarian in Lightdread City. One day, she receives a fragment of a magical book. With the help of these fragments, Karina finds a man who opposes the government's will. By studying ancient secret chambers, she gradually unravels the mystery of the unknown light. The player can rotate the terrain as if it were a roulette wheel, and light also affects objects on it.