Alanna doesn't want to go to the convent to learn to be a good-for-nothing lady and hates her inherited ability to do magic. She wishes she had been born a boy so she could become a fighter. Her twin brother Thom hates the thought of going to the palace and becoming a knight. He'd rather be a mage. So they swap places. Thom heads for the convent to learn from the mages there while Alanna disguises herself as a boy and takes Thom's place at the palace. Despite her small size and distinctive flaming red hair, she wins the other boys' respect when she takes on a bully twice her size and beats him barehanded. She also manages to win herself a magic sword through a mixture of defiance and sheer stubbornness. Both of which she will need when she becomes friends with Jonathan, the young heir to the throne. For the most powerful mage in the land wants Jonathan dead so that he can inherit the throne himself. Not content with just loosing a deadly illness on the land, the mage has designed it so that it drains any healer of all their magical energy, but requires that energy to counter the illness. And, somehow, Jonathan does not fall ill until every healer in the capital is completely drained. The only thing the mage has not counted on is the emergence of a partly trained healer from among the boys - Alanna! Having failed to get rid of Jonathan once, the mage bespells him into entering a city haunted by vicious demigods. But once again, Jonathan takes Alanna with him and they discover that her sword was designed and made to fight these particular demigods. Wielding sword and spell in unison, they fight back against the demigods and Alanna proves to herself and the entire world that although she may be only a girl, there is nothing weak about her.