Where are Amy and Dan Cahill? The two kids were last seen in Egypt, hunting for one of the 39 Clues that could make them the most powerful people on earth. But no one has seen the siblings since. Has the ruthless Irina Spasky finally tracked them down? Or worse ... the Madrigals?

Ascendant King Jaron believes that his kingdom, Carthya, is at peace, so he and his bethrothed, Imogen, are sailing home from a trade mission when their ship is attacked by Prozarians, and Jaron and several of his friends are taken prisoner; the Prozarian captain seems to believe he had something to do with his parents' deaths and they also know a great deal about Jaron's long-missing older brother, Darius, the rightful heir to Carthya--who may be...