Red Queen

Mare Barrow lives in the Stilts, a riverside village of stilt houses where Reds struggle to survive. Silvers, whose blood is silver and who can control fire, water, metal and minds, rule the kingdom of Norta and send Red teenagers without jobs to fight in a war that has lasted a century. Mare, a quick-fingered thief, is weeks away from being conscripted when a chance meeting lands her a job as a servant at the Summer Palace.

During a royal ceremony where Silver girls compete to marry the crown prince, Mare falls into the arena and lightning shoots from her hands. A Red should not have power, so the king and queen invent a story: she is a long-lost Silver lady and will marry their younger son, Maven. Now Mare must learn courtly manners, hide her red blood and train her new ability, while the elder prince, Cal, catches her eye. At the same time she becomes a spy for the Scarlet Guard, a rebel group fighting for the Reds, and learns how dangerous it is to trust anyone at court.

Cinematic and full of reversals, with a final act that resets the whole series. About 416 pages, followed by Glass Sword.