In her village underground, Jaelah knows she doesn't want to be a crystal runner. Not for her a life of filling crystals with light and life. No! Jaelah wants adventure - she wants to mix with the surface dwellers like her grandfather.The dimming of their light source gives Jaelah the chance she's been looking for. Dragging her twin brother, Aydan, behind her - she sets off to seek answers. She discovers their problems are not all that is wrong and that, in these times of terrifying change, the twins must work together with Kaen, prince of the surface dwellers, to save both their worlds.