Islands of Light in a Sea of Darkness: Tolkien's The Lord of the Rings 

The Lord of the Rings is full of bleak, frightening images, and the prevailing mood is one of fear and dread. The idea of a whole world being drowned by darkness supercharges the dramatic tension inherent in a quest story-and this is without question an extremely dark quest story. But the light is always there in the background, and occasionally it bleeds through.