Books with title Ray of Sunlight

Living in the dark, knowing the sunlight is above. Out of reach. Paulini could feel its warmth beam down on her face, like a lighthouse giving hope to a vessel. She was that vessel. An empty vessel. She is imprisoned in a hellhole, an abode of the damned. She is serving a sentence, her world not her own - no control over her life, no authority over her day, she must abide by the rules – but whose rules are they? And is she really imprisoned?