10 years ago, assassins invaded the country of Lumatere and murdered the royal family. Only Balthazar, the prince, was believed to survive. Finnikin, the son of the captain of the guard, along with numerous other Lumaterans were exiled from their country. A curse was placed upon the nation by a forest dweller, preventing anyone from entering or leaving Lumatere.

Now, Finnikin has worked with Sir Topher, the King's First Man, to try to negotiate land for the exiles. Finnikin and Sir Topher travel to a convent where they meet a novice named Evanjalin who claims to be able to lead them to Balthazar. On the journey across the land, they have a run in with a thief named Froi, and they are forced to bring him along.

Upon arriving in Sorel, Evanjalin turns Finnikin in to the authorities by saying he claims to be Balthazar. Trevanion, Finnikin's father, is in the same prison. She meets with Trevanion to tell him he must escape with his son. They do escape, and the group then heads to Yutlind, where Trevanion's guard is rumored to be hiding.

When they arrive they are attacked and Finnikin is wounded by an arrow. His wound gets infected, and Evanjalin risks her life to seek the help of the Yuts (she can speak their language). She succeeds and Finnikin begins to heal. They journey on, and find the guard in Pietrodore. They remain with them for some time, training and preparing.

After they leave, they head north. Finnikin and Evanjalin have a fight, and she goes off to a nearby exile camp. Finnikin follows, even into the fever camp. There they find the Lumateran religious leader, the priest king. The priest king joins them and they travel north to Lumatere. They gather exiles along the way with the intention of re-entering their kingdom.

Evanjalin, who can walk the sleep of those still in Lumatere, reveals some of the horrors that are happening inside. However, she is also caught in a lie about when she last walked the sleep (it is only supposed to happen when she menstruates). They also then question if she was telling the truth about Balthazar being alive. He is, in fact, dead.

Evanjalin and Froi leave, but the rest of the group continues on to Lumatere. Finnikin turns back to find Evanjalin. He is able to, but Froi has been kidnapped. With the help of the Monts (Lumaterans who live in the mountains) and Lucius (his childhood Mont friend) they are able to rescue Froi. Finnikin then learns that Evanjalin is actually Isaboe, the youngest princess who was thought to be dead. They all return to Lumatere.

With Finnikin's help, Evanjalin is able to break the curse and enter Lumatere. The impostor king, however, has set everything on fire. After much fighting, the impostor is overthrown. Isaboe wants to make Finnikin her king, but he is afraid to rule. He eventually comes around, and they decide to wed. Trevanion is reacquainted with Lady Beatriss, his lover who he thought was dead. They must begin their relationship again because she was so poorly treated by the impostor and his men, making her afraid of the touch of a man.