Sourcery (discworld, #5; Rincewind, #3)

Terry Pratchett's Sourcery is set on the Discworld, where wizards train at Unseen University in the city of Ankh-Morpork.

The story begins with Ipslore the Red, a wizard banished from the University for falling in love and marrying. As an eighth son of an eighth son, Ipslore is a wizard who has fathered eight sons. The eighth, a baby named Coin, is a wizard squared: a sourcerer, a being who channels raw, limitless magic into the world. As Death arrives for the dying Ipslore, the wizard presents Coin with a staff of octiron, an intrinsically magical metal, and prophesies that Coin will become Archchancellor, the head of Unseen University. Death insists on a loophole: The prophecy can be broken if Coin ever throws his staff away. When lightning strikes Ipslore dead, his spirit passes into the staff, binding him to it so that Death cannot claim him without destroying the child. The staff becomes Coin's teacher, whispering to him, guiding him, and punishing disobedience.

Years later, strange omens herald Coin's approach. Rincewind, a wizard who has failed to master even basic magic in sixteen years, notices the signs but is dismissed by the bursar, Spelter. Rincewind drags the Librarian, an orangutan transformed by a past magical accident, to the Mended Drum tavern, missing the night's fateful events.

Coin walks into the Great Hall during the ceremony to install a new Archchancellor. About ten years old, he disrupts the proceedings when an eighth-level wizard patronizingly demonstrates his finest spell. Coin takes the magic from the man's hands, expands it so the wizards physically stand inside the conjured landscape, then vanishes the wizard entirely. In the stunned aftermath, Spelter and Marmaric Carding, the head of one of the University's wizard Orders, form a wary alliance, recognizing Coin as a sourcerer.

Meanwhile, the Archchancellor's hat, an ancient artifact that speaks with the collective voice of past Archchancellors, has ordered a thief named Conina to steal it from the University. Conina is the daughter of Cohen the Barbarian, the greatest hero in the world, and has inherited his lethal combat reflexes, though she desperately wants to be a hairdresser. She finds Rincewind and gives him the hat, which explains that a sourcerer must never wear it because sourcery will destroy the world. It commands them to carry it across the sea to Klatch, a distant continent, where someone fit to wear it can be found.

Back at the University, raw magic floods through the stones. Coin transforms the Great Hall into a palace of glass and marble and teleports Lord Vetinari, the Patrician and ruler of the city, into the wizards' midst. When Vetinari refuses to yield, Carding turns him into a small yellow lizard. The wizards march into the city, vaporizing anyone who resists and conjuring food from thin air. Coin dissolves the wizard Orders, the rival factions within the University, builds a vast tower of solidified magic, and orders the Library burned.

Spelter grows disturbed, recognizing that the staff controls Coin. When he tries to warn the Librarian, the staff pursues and kills him. The Librarian, however, refuses to let the Library burn. When wizards arrive with torches, the ape drives them out and commands the books to fly. The volumes take wing into the Tower of Art, an ancient tower on the University grounds, along with the Patrician's lizard jar.

Rincewind, Conina, and the Luggage, Rincewind's sentient, fiercely loyal travel chest made of sapient pearwood, sail for Al Khali in Klatch. Slavers attack and steal the hatbox. In Al Khali, the group is captured and brought before Creosote, the wealthy Seriph and ruler of the city, a plump poet who cares only for stories and verse. His Grand Vizier, Abrim, has the hat and wants its power. Abrim throws Rincewind into a snake pit, where Rincewind meets Nijel the Destroyer, a scrawny young man teaching himself to be a barbarian hero from a mail-order book.

Wild magic saturates the air, and a second tower of sourcery erupts through Creosote's palace. Wizards from Ankh-Morpork pour out and kill the Seriph's guards. Abrim puts on the Archchancellor's hat, which takes over his mind and declares it will rally wizardry against sourcery. Magical war erupts between the two towers, transforming Al Khali into a nightmare of giant mushrooms, five-dimensional sugar structures, and swamps.

Rincewind, Nijel, Conina, and Creosote escape on a magic carpet from the Seriph's treasury. The Luggage, wandering the desert, fights its way to the Al Khali tower. When it charges into the hall, Abrim's concentration wavers, and Carding delivers a mental strike from the Ankh tower. Abrim implodes, releasing magic in a catastrophic burst that destroys the hat and much of the city. Carding warns that they have created a beacon attracting Things from the Dungeon Dimensions, parasitic entities drawn to magic. He grabs the staff to destroy it but hesitates, and the staff kills him.

After an argument on a desolate beach, Rincewind flies off alone to Ankh-Morpork. He finds the Library charred but realizes the books were never destroyed. In the Tower of Art, the Librarian has sheltered them all. The ape tests Rincewind by threatening to cut his wizard hat with shears, provoking a rage that forces Rincewind to discover what he is willing to fight for. He resolves to confront the sourcerer, armed only with a sock filled with a half-brick.

Atop the sourcery tower, Coin has captured the gods themselves inside a small gray pearl. With the gods imprisoned, the Ice Giants, primordial beings imprisoned at the Hub of the Discworld since the dawn of time, break free and advance on enormous glaciers. Conina, Nijel, and Creosote, transported to the Sto Plain by a reluctant genie, steal the horses of the Four Horsemen of the Apocralypse and fly to confront the Giants.

Rincewind lands atop the tower. The staff orders Coin to kill him, but Coin refuses. The staff punishes Coin with searing energy, and Rincewind knocks it from the boy's hand. Coin catches the returning staff and battles it in a blaze of octarine light—Discworld's color of magic—smashing it against the parapet and declaring, "I don't like killing people. I'm sure it can't be right" (270). The staff returns, but Coin picks it up one final time and declares he was wrong only in not throwing it far enough. Rincewind leaps into the conflagration.

Both are transported to the Dungeon Dimensions, a dark wasteland where towering Things crowd around a shrinking hole back to reality. The staff is destroyed. Rincewind tells the frightened Coin to run for the light while he holds off the Things. The Librarian, reaching through from the other side, pulls Coin to safety. The Luggage leaps into the closing darkness after Rincewind, and the hole vanishes.

On the Librarian's advice, Coin throws the pearl. It shatters, and the gods emerge in fury, their power sweeping across the world. The glaciers melt and retreat, saving Nijel and Conina from a doomed last stand.

Coin tells Conina and Nijel that Rincewind fought the sourcerer, won, and had to go. He confesses to the Librarian that his power is too great and everything he touches changes. Coin steps into a private world of his own creation, a landscape with a lake and distant mountains, the fate of all sourcerers, who never become part of the world but merely wear it for a while. The University rebuilds itself, wizards creep back, and the Librarian makes his rounds. In a niche in the Library wall sits a battered, charred hat, its letters spelling only "WIZD." The narrative observes: "No matter how far a wizard goes, he will always come back for his hat" (303).