FitzChivalry Farseer has become firmly ensconced in the queen’s court. Along with his mentor, Chade, and the simpleminded yet strongly Skilled Thick, Fitz strives to aid Prince Dutiful on a quest that could secure peace with the Outislands—and win Dutiful the hand of the Narcheska Elliania.
The Narcheska has set the prince an unfathomable task: to behead a dragon trapped in ice on the isle of Aslevjal. Yet not all the clans of the Outislands support their effort. Are there darker forces at work behind Elliania’s demand? Knowing that the Fool has foretold he will die on the island of ice, Fitz plots to leave his dearest friend behind. But fate cannot so easily be defied.
Fitz, Dutiful and the rest of his band including the Skilled and Witted coteries sail to Aslevjal. Chade assisted Fitz in leaving the Fool behind, blocking him from boarding the ships at the last moment.
After a long sea journey they arrive at Elliania's home. The royal retinue meet the Hetgurd who disagree with the slaying of IceFyre as he is a legendary figure to the Outislanders. Eventually an agreement is reached that a small detachment of Six Duchies warriors will accompany Dutiful to the island along with a group from the Hetgurd to supervise.
On arriving at Aslevjal they are met by the Fool, who flew there with Girl-on-a-dragon. The group trek across the glacier to the point where IceFyre is closest to the surface. The Witted Coterie are helpful in locating him but as the digging gets deeper are unhappy about the idea of killing the dragon. Web sends his sea bird Risk to alert Tintaglia that IceFyre lives.
It is eventually revealed that Elliania wants the dragon killed as part of an agreement to save her mother and sister. Another White Prophet, the Pale Woman, has kidnapped them and is holding them hostage. She wants IceFyre killed, as a direct counter to the Fools long-time prophecy that dragons would return to the world. The Pale Woman is responsible for the Forging, using memory stone to leech away peoples emotions. Under the glacier containing IceFyre she is using prisoners to create a memory stone dragon.
The dragon is eventually quickened using the last of the life of Kebal Rawbread, the leader of the Red Ship Raiders. Fitz and the Fool are sent back to the beach with Thick to see what became of two men sent back for supplies. Fitz and the Fool fall through a hidden crevasse in the ice into the glacier. There is no way back to the surface, so they explore the tunnels, finding themselves within the Pale Woman's icy fortress. They find the missing men in a cell, Forged. Fitz is not sure he could kill them all himself so is forced to leave them behind.
They continue through the ice, unable to find an exit until they find IceFyre frozen in the ice. Fitz finds a tunnel bored into the ice and evidence that someone attempted to dig through the dragons hide to kill him. Fitz and the Fool continue to try and escape but are captured by men at arms, Fitz is knocked out on the ice and comes around to find he and the Fool have been captured by the Woman. The Fool is dragged away, Fitz is brought to her private chamber where she attempts to seduce him. Fitz refuses and later escapes.
It is decided to release IceFyre rather than kill him. The Pale Woman sends out Kebal-as-dragon to kill the royal retinue and fight IceFyre. Burrich, nearly blind, arrives on Aslevjal alone to try and bring Swift home. When faced with the stone dragon Burrich uses the force of his Wit Power to drop the stone dragon, protecting his son Swift. Burrich is fatally injured. The dragon is finally killed by Swift, using a wizardwood arrow gifted to him by the Fool. Tintaglia and Icefyre fly away to mate.
Fitz refuses to leave Aslevjal without recovering the Fool's body. He returns to the throne room and discovers that the Fool's tattooed back skin has been flayed from him and is frozen to the floor. Fitz eventually discovers the Fool's body and carries him to the Skill Pillar. Along the way, he encounters the Pale Woman, whose hands are missing, and ignores her attempts to goad him to kill her, leaving her to die instead.
Fitz brings the Fool's body through the pillars to the market square in the Mountains they previously visited on their quest to find Verity. He builds a pyre for the Fool, and while preparing it finds the rooster crown among the Fools belongings. Fitz fits the feathers from the treasure beach into it and discovers that it is nothing more than an artifact containing the memories of several minstrels. Furious and distraught at the loss of his dearest friend, Fitz declares himself the Catalyst and claims the right to change the course of his destiny. He uses the magic of the crown and his own Wit and Skill to switch bodies with the Fool, repairs the Fool's body, and returns their spirits to their correct places, briefly mingling and becoming a single being.
After several days, the two visit Girl-on-a-Dragon, and the Fool gives her the rooster crown. She kisses him and passes Fitz's memories to him. The Fool, unable to bear their intensity, kisses Fitz to return them, finally rendering Fitz whole again.
Fitz and the Fool return to Aslevjal, and the Fool recuperates with the Black Man for a time, grappling with the surprise of experiencing life that extends pasts his prophetic ability. He decides that he needs to part ways with Fitz to prevent any undoing of their accomplishments and removes his Skill-link fingerprints from Fitz's wrists. Fitz attempts to return to Buckkeep via the Skill Pillar, but he becomes trapped in it for several months. When he finally emerges, he discovers that he has missed a last visit from the Fool, who left for him a poem and a memory-stone carving of himself, Fitz, and Nighteyes. Finally freed from prophetic expectations and his own emotional stunting, Fitz courts Molly again, eventually winning her love and settling at Withywoods with her and her children.