A party of wizards dispatched by Trymon closes in on the stone circle. Concealed nearby is a solitary, unknown figure observing the scene with interest. Inside the circle, Twoflower steps forward, politely interrupts the ceremony, and attempts to reason with the druids. While the priests stare at him in bewilderment, an old man seizes Rincewind from behind and presses a knife to his throat. The red star, now noticeably larger, rises directly over the circle’s holiest stone, prompting a cry of horror from the druids.

The old man slips a knife into Rincewind’s hand and charges into the circle, tearing through the druids with surprising speed and skill. Rincewind edges toward the altar stone while Twoflower cuts the ropes binding the young woman, who is named Bethan. Rather than showing relief, Bethan is furious. She carefully maintained her virginity for years and feels that this work has been squandered, and she had expected to join the Moon Goddess upon her death. As they argue, the archdruid swings his sickle at Rincewind. The blow misses but knocks Twoflower unconscious. Rincewind kicks the archdruid in the knee, and the old man finishes him off. The elderly man attempts to carry Bethan away but collapses under the strain of his arthritis.

Bethan carries the old man while Rincewind carries Twoflower, and the wizard becomes alarmed when he notices that the unconscious tourist feels almost weightless. They escape to a gully where a large white horse is tethered. By moonlight, the old man reveals himself as Cohen the Barbarian, the greatest warrior on the Disc, now 87 years old. Cohen grumbles about the indignities of old age, such as aching joints, piles, and his missing teeth, which force him to eat soup. He examines Twoflower and pronounces him not dead, only gone. Elsewhere on the snowfield, the group of wizards hears something approaching at high speed. Their leader fires a magical flare, temporarily blinding everyone. Before they can recover, the Luggage smashes through the entire party and vanishes into the darkness.

That night, Rincewind’s group shelters in a yurt belonging to the Horse Tribes of the Hubland Steppes. The chieftain’s grandmother, a necromancer, uses cards to divine Twoflower’s condition. Two cards have changed to reflect current events: The Star card now shows a red dot, and the Death card depicts a tiny figure being followed by the Luggage. The old woman adds a potion to Rincewind’s drink. When he swallows it, his spirit is hurled out of his body.

The narrative shifts to Unseen University, where the six surviving heads of the Eight Orders gather around Trymon, who has replaced the ornate furniture in Galder Weatherwax’s former study and introduces the concept of a written agenda, a move that unsettles the wizards. Trymon hints at intervening in another Order’s succession, a notion wholly foreign to wizards. When Rincewind is discussed, the wizards admit their magical attempts to locate him have all failed. Trymon announces he’s hired a tracker named Herenna instead. The seasoned swordswoman is currently riding with mercenaries toward the Trollbone Mountains. She reasons that Rincewind would instinctively seek the cover of the mountains, and she is glad to be putting distance between herself and Trymon, whose manner she finds deeply unsettling.

Rincewind’s spirit materializes in Death’s Domain, a dark, frozen landscape under a sky of uncharted stars and a malevolent red disc. A thin blue line runs from his ankle back toward his body, and Rincewind deduces that he’ll be permanently separated from his body if the line is severed. Following a narrow rock spur over a vast funnel through which the voices of the dead continuously whisper, he reaches a cottage far larger inside than its exterior suggests. In a stable at the back stand four well-kept horses, including a large white one. Further inside, an enormous clock with a razor-sharp pendulum ticks away the seconds of mortal lives.

A young woman named Ysabell appears and explains that she’s Death’s adoptive daughter. Ysabell welcomes Rincewind enthusiastically as she rarely has living visitors. She guides him to a door, through which he hears Twoflower enthusiastically teaching Death, War, Famine, and Pestilence a card game. The Luggage produces a rulebook from its depths for War to consult. Rincewind pulls Twoflower away, but Twoflower insists on photographing the clock with a device called an iconoscope before leaving. Ysabell reappears with a large scythe and declares she has no intention of letting them leave. She swings the blade at their lifelines, but the Luggage snaps its lid shut on the blade. Rincewind knocks Twoflower unconscious, slings him over his shoulder, and runs for the garden. Following the shimmering lifelines to the edge of the outcrop, he jumps into the soul funnel below. Death and the Horsemen ride to the edge, express mild annoyance, and agree they have time for another round of cards.

Rincewind and Twoflower’s consciousnesses land inside the Octavo itself. The wizard realizes they’re not in the physical book, but the multidimensional reality it represents. The disembodied voices of the Spells warn that Rincewind must prevent the wizards of Unseen University from extracting the Spell lodged in his head because saying all eight together before the right moment will cause terrible consequences. When Rincewind asks whether the Disc will truly collide with the red star, a Spell begins to suggest the situation is more nuanced but is cut off. The Luggage materializes inside the Octavo, baffling the Spells. Frustrated and overwhelmed, Rincewind passionately describes his longing for Ankh-Morpork. The force of this homesickness draws his spirit back along his lifeline to his body.

Rincewind awakens in the Horse Tribes’ yurt with Cohen and Bethan watching him. Twoflower also wakes, dismissing his visit to Death’s Domain as a strange dream. Rincewind slips outside to retrieve Twoflower’s iconoscope, and the imp inside the device produces its final picture, a horrifying image of what Death’s Domain actually looked like, which is far grimmer than anything Rincewind perceived. The following morning, the group sets out on horses provided by the Horse Tribes, heading for the River Smarl and, eventually, the Circle Sea. When Cohen announces that he’s coming along, Bethan promptly insists on joining to look after him. Rincewind observes what appears to be a mutual attraction between the two, and Cohen confides that at his age, the quality he values most in a woman is patience. The red star is now large enough to be visible in daylight.

By evening, the group descends from the high plains into a rocky pine forest. Cohen identifies the terrain as troll country and clarifies a common misconception: Trolls can’t digest people and subsist instead on stone, which they chew with teeth made of diamond. Cohen sends Rincewind into the undergrowth to find wild onions for soup, and a voice from a nearby rock directs him to a patch.

Back at camp, Twoflower remarks on Cohen’s toothlessness, and Cohen responds with weary resignation. Twoflower brightens and reveals he wears removable false teeth, a concept that astonishes Cohen, and begins explaining how they can be purchased. Mid-explanation, an unseen attacker strikes Twoflower.

As darkness falls, the rocks around Rincewind shift and reform into living trolls. Their leader, Kwartz, reveals that an ancient legend foretells that, when the red star lights the sky, Rincewind will appear looking for onions, and that they must help him stay alive. Kwartz introduces his group and explains a condition peculiar to very old trolls called “philosophy” in which a troll gradually stops moving and becomes a permanent boulder. An even more dangerous variation occurs when an ancient troll begins thinking purely as a rock and turns hostile to living beings.

When Rincewind and the trolls return to the campsite, they find it abandoned. They note signs of a struggle, including a trail of blood and Cohen’s bottle of liniment lying discarded in the snow. The horses and the Luggage are gone. Kwartz finds a trail leading up into the hills toward the territory of Old Grandad, a vast, ancient, aggressive troll whose thinking has long since reverted to that of a rock. Kwartz lifts Rincewind onto his shoulders, and the troll band moves out to follow the trail.