Lunar Chronicles 1: Cinder – Marissa Meyer

Humans and androids crowd the raucous streets of New Beijing. A deadly plague ravages the population. From space, a ruthless lunar people watch, waiting to make their move. No one knows that Earth’s fate hinges on one girl. . . .
Cinder, a gifted mechanic, is a cyborg. She’s a second-class citizen with a mysterious past, reviled by her stepmother and blamed for her stepsister’s illness. But when her life becomes intertwined with the handsome Prince Kai’s, she suddenly finds herself at the center of an intergalactic struggle, and a forbidden attraction.