Hans Castorp, a young engineer who has only recently finished university, travels in the years leading up to World War I from his home in Hamburg to the Swiss Alps to visit his sickly cousin Joachim. His cousin is a resident at the Berghof, which is a sanatorium for tuberculosis patients. Situated high in the mountains, the Berghof is far removed from the ordinary world down below.
Hans spends his first days strolling the grounds with Joaquim, who teaches Hans about life at the sanatorium and introduces him to several of the sanatorium’s residents. These include Settembrini, an Italian intellectual with a commitment to humanist ideals who immediately takes it upon himself to become Hans’s mentor. Hans also meets Dr. Behrens, the sanatorium’s director, and Dr. Krokowski another of the sanatorium’s doctors, who “dissects” patients’ minds and presents lectures on psychoanalysis.
From the start, Hans feels there’s something odd and vaguely unsettling about the Berghof, though the strange atmosphere simultaneously enchants him. Residents and staff alike adopt a detached, indifferent attitude toward suffering, illness, and death. Patients seem to get worse, not better, under Behrens’s care. It’s not uncommon for residents’ discharge dates to be postponed months or even years. Even stranger, nobody seems to mind sticking around: in fact, it’s not uncommon for discharged residents to return to the Berghof, having struggled to readapt to ordinary life. Over the course of days and then weeks, Hans acclimates to life at the Berghof, and he starts to live as the permanent residents do.
Hans initially plans to stay only for three weeks, as he’s scheduled to start his first real job upon his return. But just as he’s getting ready to leave, he falls ill. Behrens performs a precautionary X-ray on Hans’s chest and discovers a “moist spot” in his lungs—meaning Hans has tuberculosis and must remain at the sanatorium until he recovers. Hans takes this news in stride. His reaction disturbs Joachim, who, unlike most other residents of the Berghof, wishes to re-enter society as soon as possible, determined to return to his military service.
Following his diagnosis, Hans commits to his new existence as a resident of the Berghof, never seeming to mind when Behrens repeatedly pushes back his discharge date. Instead, he occupies himself with various intellectual pursuits, becoming deeply interested in biology, human anatomy, and philosophy. He regularly ventures out to a nearby meadow to “play king,” or indulge in lofty philosophical musings about life, death, and the passage of time. Settembrini regularly lectures Hans on humanism and urges Hans to recover, leave the Berghof, and become a productive member of society. Hans, however, stubbornly dismisses this advice and continues to waste his days on self-indulgent musings.
In addition to Hans’s intellectual pursuits, he also falls for an ill-mannered and sensuous young Russian woman, Clavdia Chauchat. Though initially Clavdia’s poor manners disgust Hans, he comes to understand Clavdia’s rudeness as a type of freedom—and one she has earned through physical illness, specifically. Following this realization, Hans becomes infatuated with Clavdia despite Settembrini’s warnings about Clavdia and the dangerous “Asiatic” principles she represents.
Hans’s romance culminates during the sanatorium’s Walpurgis Night festivities, when he and Clavdia have an intimate and flirtatious conversation. Clavdia gifts Hans a photo of her X-ray and ridicules Hans for what she considers his characteristically German, bourgeois sensibilities. Hans nevertheless declares his love for Clavdia. Clavdia shocks Hans by announcing that she’s leaving the Berghof tomorrow, though she coyly adds that she’ll likely return at some point. Hans is heartbroken to see her go.
Toward the end of Hans’s first year at the Berghof he meets Naphta, a Jesuit and a professor of classical languages who becomes Settembrini’s intellectual adversary: while Settembrini espouses Enlightenment values of humanism and democracy, Naphta has radical, communist sympathies that Settembrini views as regressive and anti-humanitarian. The men frequently debate their respective positions, and Hans and Joachim frequently observe these often-fiery arguments.
In September, a little over a year after Hans’s arrival at the Berghof, Joachim leaves to resume his military service, a decision he makes against Behrens’s advice. Hans, meanwhile, remains at the Berghof. Without Joachim for company, he befriends two residents, Wehsal and Ferge. His favorite uncle, James Tienappel, also comes to visit him. James attempts to convince Hans to leave the Berghof but is unsuccessful. Though strangely enchanted by the sanatorium, just as Hans was when he first arrived, James ultimately leaves in a hurry, apparently disgusted by Dr. Behrens’s particularly gruesome description of a decomposing body. He does not say goodbye to Hans.
That winter, Hans takes up skiing. On one outing, he ventures deep into the woods and gets lost when a storm hits. He takes shelter beside a shed, falls asleep, and has a dream about old, half-naked witches dismembering a small, blond-haired child. Hans awakes and reflects on the interconnectedness of illness, death, and sickness. He concludes that the only thing stronger than death is love—not reason, as Settembrini would argue. Eventually he finds his way back to the Berghof.
By late spring, the strain of Joachim’s service has taken a toll on his health, forcing him to return to the Berghof. His health continues to deteriorate, and eventually he dies. Following Joachim’s death, Hans loses what remaining motivation he had to make good use of his time, and he gives himself over to the malaise and meaninglessness that characterizes life at the Berghof for so many of its residents.
Clavdia returns to the Berghof, but she’s accompanied by a lover: Mynheer Peeperkorn, an old, retired colonial Dutchman who loves to drink, entertain, and indulge in all manner of decadent pleasures. He captivates his audiences with his grand gestures and bravado, though much of what he says is utter nonsense. In private, Clavdia admits to Hans that she is drawn to Peeperkorn’s dominance and takes pleasure in submitting to him. Hans responds ambiguously to Peeperkorn’s arrival. On the one hand, he continues to pine for Clavdia and is jealous of her new lover. On the other hand, he quite likes Peeperkorn and seems to want Peeperkorn to like him back. Settembrini doesn’t understand Hans’s fascination with Peeperkorn and tries to convince Hans that the man is a hedonistic fool, but to no avail. Peeperkorn eventually confronts Hans about his and Clavdia’s romantic history, but he continues to behave amiably toward Hans, nonetheless.
One day, Peeperkorn leads Clavdia, Hans, Settembrini, Naphta, Wehsal, and Ferge on an outing to a nearby waterfall for a picnic. He tries, as usual, to engage his audience with his commanding presence and riveting rhetoric, but the great roar of the waterfall drowns out his words, greatly dispiriting him. He dies by suicide after returning to the Berghof that night, having injected himself with poison. Clavdia leaves after Peeperkorn’s suicide, and Hans never sees her again.
Eventually a “Great Stupor” descends upon the Berghof, and residents become restless, agitated, and generally gloomy. They occupy themselves with tedious activities and silly parlor games to pass the time.
Some years into Hans’s stay, a young woman named Elly Brand arrives at the Berghof, and eventually the other residents discover she has a hidden talent: she has extrasensory perception and can communicate with the spirit world. Krokowski, whose interests have shifted toward more supernatural matters over the years, starts conducting hypnosis sessions and séances with Elly, which some residents attend. Hans attends one séance and asks, against his better judgment, for Elly to manifest Joachim’s spirit. She does so, and the experience deeply disturbs Hans.
As time passes, the political situation in the world below worsens to the point where war seems inevitable. The atmosphere of the Berghof turns tense, as well. Settembrini and Naphta get into a philosophical argument that becomes so heated that Naphta challenges Settembrini to a duel. When the appointed hour of the duel arrives, Settembrini, an avowed pacifist, refuses to shoot Naphta. Instead, he aims pistol upward and fires directly into the sky. Naphta, infuriated by Settembrini’s “cowardice,” responds by shooting himself in the head. Naphta’s suicide deeply affects Settembrini, who from that point on spends most of his time in bed, becoming a shell of his former self.
Meanwhile, tensions “down below” continue to brew, though Hans stopped paying attention to the happenings of the real world long ago. In total, Hans spends seven years at the Berghof. In his seventh year, war is finally declared, at the sanatorium erupts in chaos as residents rush to pack their things and leave. At long last, it’s time for Hans, too, to leave the Berghof.
The novel closes with a grim description of Hans fighting on a battlefield alongside thousands of other young men. The narrator doubts that Hans will survive the war, though his exact fate remains unknown.
