Diamond Dionne is a daring treasure hunter with a hidden agenda. When she and her sidekick, Amethyst Angelova, break into an ancient crypt, they find themselves in the clutches of Prince Renaud, a tortured soul driven by a thirst for revenge, along with his pet ferret, Fausto. In exchange for their freedom, Diamond proposes an unlikely deal—they must find the Louis XIV Sunburst Pendant, a mysterious item that can bend anyone's will with the power to break curses.

Deals with otherworldly characters are never what they seem, but that doesn't stop Diamond and Renaud from trying to one-up each other, flinging empty promises and wagering with the only currency that matters—their hearts. The fearless foursome traverses perilous landscapes filled with dark creatures while contending with Diamond's thieving godmother and the Demon Second Class, Philly, who requires Renaud to collect souls for him.

While Diamond tries to weasel out of her deals with demigods and demons and Renaud counts the souls he's collected and lost, a shocking turn of events forces them to embark on a daring search for Diamond's missing mother. As their enemies close in on them, Renaud and Diamond must join forces with enemies and friends alike while their affections are tested and stretched to the hilt.

Can an unapologetic treasure seeker and a prince with burdened soul open their hearts to true love and survive the secrets of the fabled Sunburst with its Faustian powers intact?