Fortune's Fool (Five Hundred Kingdoms)

The seventh daughter of the Sea King, Ekaterina is more than a pampered princess--she's also the family spy. Which makes her the perfect emissary to check out interesting happenings in the neighboring kingdom...and nothing interests her more than Sasha, the seventh son of the king of Belrus. Ekaterina suspects he's far from the fool people think him. But before she can find out what lies beneath his facade, she is kidnapped!
Trapped in a castle at the mercy of a possessive Jinn, Ekaterina knows her chances of being found are slim. Now fortune, a fool and a paper bird are the only things she can count on--along with her own clever mind and intrepid heart....