Marie Reinhart is an NYPD detective on the trail of a serial killer. When she sleeps, though, she dreams of other lives; she dreams of being a knight, in strange wars and strange worlds. On the other side of the city, Nessa Roth is a college professor trapped in a loveless marriage, an unwilling prop in a political dynasty. She's also a fledgling witch, weaving poppets and tiny spells behind closed doors.

When Marie's case draws her into Nessa's path, sparks fly. What comes next is more than a furtive whirlwind affair; it's the first pebbles of an avalanche. Nessa and Marie are the victims of a curse that has pursued them across countless lifetimes; a doom designed to trap them in a twisted living fairy tale, with their romance fated to end in misery and death.

They aren't going out without a fight. As they race to uncover the truth, forces are in motion across the country. In Las Vegas, a professional thief is sent on a deadly heist. In a Detroit back alley, witches gather under the guidance of a mysterious woman in red. Just outside New York, an abandoned zoo becomes the hunting-ground for servants of a savage and alien king. The occult underground is taking sides and forming lines of battle. Time is running out, and Nessa and Marie have one chance to save themselves, break the curse, and demand justice.

This time, they're writing their own ending.