The Light Fantastic

The narrative opens as the failed wizard Rincewind and the Discworld's first tourist, Twoflower, are falling off the edge of the world. At Unseen University, the premier college of magic, the most powerful grimoire, the Octavo, begins to react violently. The book contains the eight Great Spells of the Disc, but one has been lodged in Rincewind's mind for years. Galder Weatherwax, the Chancellor of the University, and other senior wizards realize the book's agitation is an attempt to prevent the eighth spell from being lost forever.

The Octavo unleashes a wave of magic that readjusts reality. Rincewind awakens hanging from a tree in the enchanted Forest of Skund, where he discovers the trees can talk. Nearby, Twoflower lands safely in a lake inside the neolithic spaceship he and Rincewind had used to escape the nation of Krull. Twoflower's sentient, multi-legged suitcase, the Luggage, also reappears and sets off to find its owner. Rincewind and Twoflower are soon reunited in the forest.

At Unseen University, the magical backlash has transformed the head librarian into an orangutan. To understand the recent events, Galder and the heads of the other seven magical Orders perform the Rite of AshkEnte to summon Death. Death reveals an ancient prophecy: the spells must be read together on Hogswatchnight, just two months away, or the Disc will be destroyed. He informs them that Rincewind is in the Forest of Skund, which sparks a competitive race among the wizardly Orders to find him and capture the spell. Galder's ambitious subordinate, Trymon, secretly observes the summoning and begins his own research into the prophecy, seeking power for himself.

Lost in the forest, Rincewind and Twoflower meet a gnome named Swires, who leads them to a gingerbread cottage for shelter. The cottage is maintained by the residual magic of a long-gone witch. Soon, various factions of wizards tracking Rincewind converge on the cottage, leading to a chaotic magical battle from which Rincewind and Twoflower escape on a magic broomstick.

Meanwhile, Galder crafts a magic arrow designed to create a path for the Spell to travel from Rincewind directly into his own mind. Trymon attempts to assassinate him, but Galder's protective spells thwart the attack. Galder fires the arrow, but it misses Rincewind and strikes the Luggage, causing it to vanish. Flying high above the clouds, Rincewind and Twoflower see a malevolent red star that appears to be on a collision course with the Disc. Later, when Galder performs a ritual to draw the Spell to him, the Luggage materializes in his magic circle. Galder vanishes, and the Luggage rampages through the University before escaping. With Galder gone, Trymon is inaugurated as the new head of his Order.

The broomstick eventually fails, and Rincewind and Twoflower crash onto a large flying rock piloted by a druid named Belafon. He explains he is a druid delivering a replacement part for the great stone circle on the Vortex Plains, a massive stone computer used for astronomical predictions. At the circle, Rincewind has a vision in which the other seven spells, speaking to him from within the Octavo, reveal that he has an important role to play.

While at the circle, they witness a druidic sacrificial ceremony. It is violently disrupted by Cohen the Barbarian, the Disc's greatest hero, now an 87-year-old man suffering from numerous ailments. He frees the sacrifice, a young woman named Bethan, who is furious at being rescued. During the ensuing fight, a druid strikes Twoflower on the head with a sickle, causing his spirit to separate from his body.

The group seeks help from a nomadic Horse Tribe. The chieftain's grandmother, a necromancer, gives Rincewind a potion that allows his spirit to leave his body and follow Twoflower's. Rincewind travels to the Domain of Death, where he finds Twoflower teaching Death and the other three Horsemen of the Apocalypse, War, Famine, and Pestilence, how to play bridge. Rincewind rescues Twoflower, and they escape from Death's daughter, Ysabell, with the help of the Luggage, which has also entered the transitional state. They return to their bodies, and Rincewind has another vision in which the spells warn him not to let the spells be spoken too soon.

Trymon hires a swordswoman, Herrena the Henna-Haired Harridan, to capture Rincewind. She and her mercenaries capture Cohen, Bethan, and the revived Twoflower. Rincewind, meanwhile, encounters a group of sentient trolls who know of a legend that they are destined to help him. Herrena's party takes shelter in a cave, which is actually the mouth of Old Grandad, a mountain-sized troll. They light a fire on his tongue, waking him. As the giant troll rises, Rincewind's troll allies attack Herrena's men, and the prisoners escape. The rising sun turns Old Grandad back to stone.

The group reunites, and Cohen acquires a set of dentures made from a troll-tooth diamond. He and Bethan decide to get married. Soon after, Herrena recaptures Rincewind and Twoflower, but Cohen and Bethan ambush the mercenaries and rescue them. They travel to a city that has been taken over by the star people, a doomsday cult that blames magic for the approaching star. When cultists confront Rincewind, the Spell in his head acts independently, vaporizing a man with a blast of magic. Fleeing the mob, Rincewind, Twoflower, and Bethan stumble into a magical, wandering shop, a taberna vagante, whose cursed shopkeeper agrees to transport them to Ankh-Morpork.

They arrive in Ankh-Morpork to find the city in chaos, with the red star now larger than the sun. Rincewind, Twoflower, and Bethan use a secret entrance to get into Unseen University, where Rincewind uses a flicker of his own magic to free the wizards locked in an underground chamber. They learn that Trymon has stolen the Octavo and taken it to the top of the Tower of Art. There, they find that Trymon's mind has broken from the strain of the spells, creating a gateway through which creatures from the Dungeon Dimensions have possessed him. The other senior wizards are turned to stone. Rincewind fights the possessed Trymon, and with a final blow from Twoflower's sword, the creature falls from the tower, pulling Rincewind with it.

Rincewind survives by catching a ledge and is rescued by Cohen, who has also arrived in the city. Seven fireballs, the freed spells, rise from the bottom of the tower and return to the Octavo. Exhausted, Rincewind forces the eighth spell out of his head and back onto the final page. He reads the spells aloud. The magic causes the red star to burst open, revealing eight newly-hatched, tiny discworlds, each on its own turtle and elephants. Great A'Tuin, the world turtle, has come to this spot in space for the hatching of its offspring. The new turtles follow their parent into the cosmos. The Octavo is swallowed by the Luggage for safekeeping. In the aftermath, a newly confident Rincewind decides to re-enroll at the University. Twoflower, feeling his adventures are over, decides to return home. As a parting gift, he gives the Luggage to Rincewind. Rincewind watches Twoflower's ship depart before heading back to the University, with the Luggage trotting faithfully behind him.