The fourth installment in the Heir Chronicles series by New York Times and USA Today bestselling author Cinda Williams Chima.

They called it the Thorn Hill Massacre—the brutal attack on a once-thriving Weir community. Though Jonah Kinlock lived through it, he did not emerge unscathed. Like the other survivors, Jonah possesses unique magical gifts that set him apart from members of the mainline guilds. At seventeen, he has become the deadliest assassin in Nightshade, a network that hunts the undead.

Emma Claire Greenwood grew up worlds away, raised by a grandfather who taught her music rather than magic. An unschooled wild child, she runs the streets until the night she finds her grandfather dying, gripping a note warning Emma that she might be in danger. The clue he leaves behind leads Emma into Jonah's life—and a shared legacy of secrets and lingering questions: Was Thorn Hill really a peaceful commune? Or was it, as the Wizard Guild claims, a hotbed of underguild terrorists?

As members of the mainline guilds start turning up dead, the Wizards blame Nightshade, and it's up to Jonah and Emma work to uncover the truth...before whoever planned the Thorn Hill Massacre strikes again.