A song of wraiths and ruin

"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 his younger sister, Nadia, as payment to enter the city, Malik strikes a fatal deal. Kill Karina, Crown Princess of Ziran, for Nadia's freedom"--OCLC.