Darcia Bonnet aims to become the Mistress of the Wicked, the darkest witch souls, to harness their power and bring her sister back from the beyond. However, to achieve this, she must kill thirteen witches. As Darcia relentlessly hunts witches through the winding streets of New Orleans, she crosses paths with Valens Mariquise, who is burdened by a cruel curse. Darcia may be his last hope. The two damned souls form a pact and must realize that their fates are now inextricably linked.