A fantasy series following the story of a 17-year-old girl named Mare Barrow who lives in a universe divided by blood — those with common, Red blood serve the Silver-blooded elite, who are gifted with superhuman abilities. Mare is a Red, scraping by as a thief in a poor village, until a twist of fate means she discovers an ability of her own. To cover this impossibility up, she is forced to pretend she is a Silver. Betrothed to one of the princes, she enters a dangerous game of survival where one wrong move can lead to her death. As she is drawn further and further into the Silver world, she uses her new position to help an organization of Reds who are planning a rebellion, risking everything – her heart and her life.