The building reaches full occupancy and a bottle of champagne explodes on Laing's balcony, sparking his first dispute with upper-floor neighbors.

A blackout on the 10th-floor shopping concourse triggers a stampede that injures dozens, launching the building's descent into chaos.

During the blackout chaos, Wilder drowns an Afghan hound belonging to a top-floor resident in the building's swimming pool.

Laing and Eleanor Powell watch from a balcony as the 40th-floor jeweler's body falls past them and crushes a car below.

Wilder returns from filming a prison documentary outside to find the high-rise transformed: lobby graffitied, elevators stalled, and cars covered in debris.

After Helen pleads with Wilder to move the family out, Wilder resolves instead to summit the building and test himself against it.

Royal's clan ambushes Wilder on the 37th floor, beats him unconscious with clubs, and he wakes under the bright lobby lights below.

Laing steps outside the building and is overwhelmed by the alien atmosphere of fresh air and sunlight, returning inside and never leaving again.

After Alice arrives from the lower floors seeking electricity, Laing invites her to move in and resolves to remain on the 25th floor.

The large floor-based clans dissolve into isolated groups barricaded in individual apartments, and the sporadic violence that remains becomes far more extreme.

Wilder boards the last elevator of the afternoon heading upward, finally abandoning his wife and children on the lower floors.

Wilder breaks into Charlotte Melville's apartment, marks his body with red wine, rapes her, and records her cries to play back to her.

Wilder kicks down the door to Royal's penthouse, and when Royal attacks with his chromium cane, Wilder shoots him in the chest.

Wilder steps onto the building's roof and finds a group of women who encircle him with knives drawn from their aprons.

Laing finds the wounded Royal dragging himself down the stairs and helps him to the 10th-floor pool, which has become a mass grave.

When the high-rise reaches full occupancy, a series of blackouts and provocations escalates into open floor-based warfare among the building's middle-class residents. Wilder, a second-floor documentarian, secretly drowns a top-floor resident's Afghan hound during the chaos, and the violence spreads until a jeweler falls to his death from the 40th floor. Returning from a stint filming outside, Wilder resolves to summit the building by any means necessary, while Laing discovers he can no longer bear the outside world and retreats permanently into the high-rise. As floor-based clans dissolve and violence intensifies, Wilder abandons his family and wages a brutal final ascent, committing rape and assault on the upper floors before shooting the building's architect Royal in the penthouse. The women's commune that has quietly taken control of the upper floors encircles Wilder with knives on the roof, implying his slaughter. Below, Laing helps the dying Royal to a mass grave in the drained pool and settles contentedly into his new life.

The headline events driving the high-rise's collapse from order to barbarism.

Laing attends Charlotte Melville's party and meets Richard Wilder, a documentarian who plans to film the pressures of high-rise life.

Lower-floor residents hold rowdy parties for their children and pour drinks from their balconies down onto the cars of upper-floor residents.

A fifth-floor masseuse is trapped at the elevator and beaten by a mob; Laing tries but ultimately fails to escort her to safety.

Top-floor residents padlock the rooftop sculpture garden, denying access to the lower-floor children it was designed for.

Laing and Charlotte have sex after a frightening night of chaos, an encounter Laing immediately recognizes as an ending rather than a beginning.

Wilder takes his young son to the 35th-floor pool but is barred from passing by Paul Crosland's clan on the 25th floor.

A lower-floor woman riding the freight elevator guides Wilder through the building and reveals a women's commune established on the 29th floor.

Royal walks his Alsatian on the rooftop as a flock of gulls descends to scavenge the remains of a cocktail party.

Royal's Alsatian is returned in an elevator covered in blood; Royal delays thirty minutes before going to rescue his wife from the lower floors.

Royal descends to the 10th-floor concourse with his bloodied dog and finds Wilder leading his lower-floor clan in battle over an empty classroom.

Steele corners a cat in an empty apartment with a curtain rod and suffocates it while Laing watches in horror and fascination.

Wilder approaches two women on the 20th floor and offers to feature them in his documentary, but they dismiss him and send him away.

Wilder uses a whimpering poodle as bait to lure two women out of a 35th-floor barricade during his final push toward the summit.

Royal steps onto the roof to find its surfaces streaked with blood and covered in strange symbols of an unknown calligraphy.

Laing carves and serves Royal's roasted Alsatian to Eleanor and Alice as their first substantive meal in weeks.

Before the high-rise fully descends into violence, its residents perform the social rituals that foreshadow its collapse: raucous floor parties, petty territorial disputes, and the first eruptions of mob violence against vulnerable neighbors. Wilder attempts several early ascents of the building, encountering a women's commune and getting beaten unconscious by Royal's clan, while Laing is drawn into reluctant intimacy with his neighbors Charlotte and later Eleanor. Royal and his white Alsatian become symbols of upper-floor authority, but the dog's brutal injury at the hands of lower-floor clans signals the beginning of Royal's erosion. As isolated groups replace the clans, formerly mild-mannered residents like Steele commit acts of casual cruelty, and Wilder's ascent grows more savage and ritualistic, culminating in war paint and lost speech. The women's commune extends its reach quietly upward, leaving signs the men fail to recognize, until Laing finally serves his first real meal in weeks and the building settles into its grim new domestic order.

The overlooked moments that shaped life and death inside the high-rise.

Residents gather in the concourse cinema to watch an amateur pornographic film shot inside the building during the early nights of disorder.

Psychiatrist Talbot tells Laing that residents welcome inter-floor hostility and that the building's carnival atmosphere depends entirely on this animosity.

Wilder outlines the pathology of the high-rise for his documentary, identifying three social classes divided by floor height and access to amenities.

A lower-floor blackout angers residents who clamor for the elevators; when one finally arrives, it opens to reveal a badly beaten second-floor resident.

Royal and his wife Anne pack their belongings to move out but realize too late that the elevators have been commandeered by other floors.

Royal and Pangbourne plan to ingratiate themselves with middle-floor residents, hoping to use them as a buffer against the lower-floor clans.

Royal and Jane Sheridan have sex in an empty 39th-floor apartment while Anne sits nearby in silent, tribal approval of the clan leader.

Laing's clan barricades inside Adrian Talbot's apartment and huddles around torches, their nighttime raids recorded only by the flash of polaroid cameras.

Wilder rouses his neighbors for an upward raid by fabricating a pedophilia accusation against the psychiatrist Adrian Talbot.

A police officer approaches the building, but three neatly dressed residents leaving for work calmly pacify him and send him away.

Royal and Pangbourne continue staging elaborate formal dinners by candlelight as the women servants lay silverware amid the penthouse's growing garbage.

Pangbourne's gang seizes the rooftop, throws two captive residents over the parapet, and dismisses Royal's authority with a flick of the wrist.

Royal releases the dogs he had caged in the rooftop sculpture garden, sending them scattering down the stairwells, before retreating alone to his penthouse.

Laing finds Eleanor Powell in an empty apartment, allowing a starving cat to feed from a wound on her wrist as she watches a muted TV.

Laing watches the newly opened second high-rise experience its first blackout and contentedly welcomes its bewildered residents to their new world.

From the earliest signs of disorder, the residents of the high-rise reveal that they don't merely tolerate the building's violence but actively welcome it as liberation from their sterile, conformist lives. Key figures like Wilder and Royal make choices that lock them into escalating spirals of self-destruction: Royal cannot bring himself to leave when he has the chance, while Wilder sheds language, identity, and family in his irrational ascent. As the building's men pursue their private fantasies of domination, a women's commune quietly consolidates power in the upper floors, operating entirely beyond the awareness of the three male protagonists. The final authority figures — Pangbourne and then Royal — are stripped of their power in turn, while Laing builds the most durable arrangement of all: a domestic unit sustained by dependency and self-interest. The novel closes with the revelation that this process is not unique to one building, as a second high-rise goes dark and Laing watches its bewildered new residents begin their own descent with knowing satisfaction.

The decisions, discoveries, and moral thresholds that defined the building's new order.