A Song of Wraiths and Ruin by Roseanne A Brown

For Malik, the Solstasia festival is a chance to escape his war-stricken home and start a new life with his sisters in the prosperous desert city of Ziran. But when a vengeful spirit abducts Malik’s younger sister, Nadia, as payment into the city, Malik strikes a fatal deal—kill Karina, Crown Princess of Ziran, for Nadia’s freedom.

But Karina has deadly aspirations of her own. Her mother, the Sultana, has been assassinated; her court threatens mutiny; and Solstasia looms like a knife over her neck. Grief-stricken, Karina decides to resurrect her mother through ancient magic . . . requiring the beating heart of a king. And she knows just how to obtain one: by offering her hand in marriage to the victor of the Solstasia competition.