Samantha Cray has a secret hidden in her blood: she is the Wielder, destined to become one of the Circle-a group dedicated to the Light, who fight the Dark in all its manifest forms. After a tragedy, Samantha decides to stay in Europe where she learns not only the secrets of her blood, but of the world as we know it, and when her best friend, Fran, visits her in London, she not only joins the Circle, too, she becomes so much more than a friend. Together they must learn and learn fast, not just who to fight, but how to fight, because the Dark will stop at nothing...