Ailsbet is daughter of the cruel and powerful King Haikor of Rurik. He rules with an iron fist, stealing the male “taweyr” from his lords as a tax. But he despises the neweyr and since his wife died, has done nothing to keep the land fertile. When Ailsbet shows no neweyr, everyone considers her unweyr, without any magic. Her brother Edik is the only hope of a proper heir to their father’s taweyr, but when he is asked to prove his magic, Ailsbet realizes she is the one helping him again. She isn’t unweyr, after all, but ekhono—she has the wrong magic—and if she is discovered, she will be burned. Marlissa (Issa) is the daughter of King Jaap of Weirland, the smaller and more northern of the two islands of the weyr. She comes into her neweyr properly and when her father asks her permission to agree to a betrothal to young Prince Edik of Rurik, she agrees for the sake of the two kingdoms. When she goes to meet Edik, however, she finds that he is a selfish boy and she falls hopelessly in love instead with Duke Kellin, a man who is working behind the scenes against King Haikor, and who is betrothed to Ailsbet, a woman who should be her enemy but as they spend more time together, seems instead to be the one person in Rurik who can truly understand how Issa feels.

Two princesses, two kingdoms, two magics. They're meant to be enemies, rivals for power and love, but turn out to be fast friends. After Issa has “proven” that she has double weyr by destroying the Tower holding Ailsbet, she goes back to Weirland. Her betrothed, Edik, is dead, and Duke Kellin has been betrayed to King Haikor. Now she has to face the possibility that Haikor will come to battle against Weirland. If so, Issa must figure out how to use the neweyr in battle. Meanwhile, Princess Ailsbet has been sent in exile to Aristonne. She seeks out her old music teacher, Master Lukacs, and becomes a servant to Prince William of Aristonne.

Two princesses, two kingdoms, two magics. Kellin didn't intend to become king. But he accepts it because Rurik is in desperate need. So what will happen when the true queen, Aislbet returns? A sweeping epic historical fantasy inspired by Tudor England, and the real life rivalry of Queen Elizabeth and Mary Queen of Scots.

The epic conclusion to The Books of the Weyr. Prince William has some tricks up his sleeve. He has learned about the original magic of Aristonne, and he brings his armada with him against Rurik. This time, he will win. The memory of his father’s death at King Haikor’s hand haunts him. Does Ailsbet love him enough to surrender him on the field of battle? And what of Kellin and Issa? They’re married, but is their love enough to save Weirland?