Born amid her parents’ ruthless struggle to unify and strengthen their kingdom, Juana, at the age of sixteen, is sent to wed Philip, heir to the Habsburg Empire. Juana finds unexpected love and passion with her dashing young husband, and at first she is content with her children and her married life. But when tragedy strikes and she becomes heir to the Spanish throne, Juana finds herself plunged into a battle for power against her husband that grows to involve the major monarchs of Europe. Juana vows to secure her crown and save Spain from ruin, even if it costs her everything.