When four strange, and strangely talented, youngsters are brought to Winding Circle by master sorcerer Niko they find themselves drawn together in a Circle of Magic - a circle that binds them despite their differences.

For years, the Empress of Namorn has pressed her young cousin, Lady Sandrilene fa Toren, to visit her vast lands within the Empire's borders. Sandry has avoided the invitation for as long as it was possible. Now, Sandry has agreed to pay that overdue visit. Sandry's uncle promises guards to accompany her. But they're hardly a group of warriors! They're her old friends from Winding Circle: Daja, Tris, and Briar. Sandry hardly knows them now. They've grown up and grown apart.

In the medieval and fantastic realm of Tortall, Keladry of Mindelan (known as Kel) is the first girl to take advantage of the decree that permits females to train for knighthood. Up against the traditional hazing of pages and a grueling schedule, Kel faces only one real roadblock: Lord Wyldon, the training master of pages and squires. He is absolutely against girls becoming knights. But Kel is not a girl to underestimate.

Alanna of Trebond is no ordinary girl: her dream is to become a knight. So she disguises herself as a boy and begins training at the palace of King Roald. Alanna quickly finds out that the road to knighthood is not an easy one, but her skills and stubborness help her become friends with Prince Jonathan and his followers. At the same time, Alanna makes an enemy of the prince's uncle, the overly charming Duke Roger.

When Daine comes down from the mountains, she carries with her two things: a dark secret about her own past, and a strangely powerful magic that even she doesn't understand.