A young man named Aaron Boone](/actor/craig-sheffer) is haunted by recurring nightmares of a mysterious city known as Midian—a sanctuary for monsters seeking redemption and acceptance. In an effort to deal with these unsettling visions and at the urging of his girlfriend Lori, Boone consults the psychotherapist Dr. Phillip K. Decker, played by David Cronenberg. Decker manipulates Boone into believing he has committed a series of horrific murders. The sinister twist is that Decker himself is a serial killer, concealing his true identity behind a grotesque mask, and targeting families he deems "breeders." In a calculated move, he tries to frame Boone for his own bloodshed, tricking him by providing a bottle of lithium, which is a hallucinogenic drug instead, and gives Boone twenty-four hours to turn himself in.
As Boone wanders through the city, disoriented and under the influence of drugs, he gets struck by a truck and ends up in the hospital. There, he hears the frantic pleas of a man named Narcisse, who believes Boone is a messenger from Midian sent to test him. In a harrowing act, Narcisse tears the skin from his face, revealing his "true face," and then divulges the location of Midian to Boone. After a narrow escape from the hospital, Boone finds Midian—a sprawling city shrouded beneath a vast graveyard. Here, he encounters two supernatural beings, Kinski and Peloquin, who reside in this hidden world. Kinski argues that Boone should stay, but Peloquin perceives that Boone is fundamentally a "natural," asserting he should not survive. Despite his claims that he is a murderer deserving of a place among the Nightbreed, Peloquin exposes his monstrous nature by biting Boone before he manages to flee.
However, Boone quickly finds himself in dire straits again, facing a cadre of police officers, led by Decker, lying in wait outside the city's gates. In the ensuing chaos, Boone is shot by the police after Decker falsely claims he is armed. Miraculously, Boone returns to life at the morgue, transformed into a Nightbreed due to Peloquin's bite. Upon his revival, he returns to Midian, where Narcisse has also reappeared. Boone learns the laws and lore of Midian from Dirk Lylesburg, the Nightbreed leader, who completes Boone's induction through a ritual involving the blood of Baphomet, the deity of Midian.
Meanwhile, Lori is determined to understand Boone's sudden disappearance and ventures into Midian herself, befriending a woman named Sheryl Anne along the way. When she enters the cemetery, she discovers a dying creature. At the urging of a Nightbreed member named Rachel, she rescues the creature, which transforms into a little girl, Babette, who is too sensitive to sunlight. When Lori inquires about Boone, Lylesburg coldly informs her that he is now one of the Nightbreed and can no longer return to her world. As Lori attempts to navigate her way into Midian, she is met with terror when confronted by Peloquin and discovers Sheryl Anne's lifeless body, revealing that Decker is her new boyfriend. Decker's pursuit of Lori leads to a confrontation in the cemetery, where just as he is about to kill her, Boone emerges. Decker stabs him but finds Boone is impervious to death due to his newfound supernatural state.
Decker escapes, and Boone brings Lori into Midian, where she gradually regains consciousness. Rachel enlightens her on Midian’s history, revealing that its monsters were once peaceful beings hunted nearly to extinction by humanity. However, amidst this intricate tapestry of revelations, Boone and Lori are banished from Midian by Lylesburg. As calamities unfold, Decker interrogates a local mechanic who once wanted to join the Nightbreed and learns their vulnerabilities. He proceeds to massacre the residents of the hotel where Boone and Lori are staying.
Drained by grief and hunger, Boone succumbs to temptation and takes a taste of blood when he stumbles upon the murder scene. Eventually captured by the police, Boone’s fate hangs by a thread—until the local militia, spearheaded by the ruthless Captain Eigerman, prepares to launch an offensive against Midian. They enlist the aid of a drunken priest named Ashberry, who is meant to rally divine support for their assault. Meanwhile, Lori, Rachel, and Narcisse work frantically to free Boone. When they reunite, Lori professes her love for him, even in his monstrous form, rejuvenating Boone’s resolve.
In a fierce battle, Ashberry is appalled to find innocent women and children among the Nightbreed and attempts to halt the onslaught, only to be violently subdued by Eigerman. In a moment of transformation, Ashberry finds himself at the feet of Baphomet. After casting aside his cross and Bible, he approaches the deity, only to be scalded by Baphomet’s blood, which molds him into something else entirely. The Nightbreed mounts a counter-offensive, yet Boone learns from Lylesburg that Baphomet is set to eradicate Midian. Urgently, he commands the release of the Berserkers—a feral breed cloistered due to their madness—into the fray.
The Berserkers unleash chaos upon the human attackers, twisting the battle's momentum. In a climactic clash amidst the crumbling remnants of Midian, Boone faces Decker. In a fierce confrontation, Boone kills Decker and then confronts Baphomet, who reveals the prophecy surrounding Midian's demise and charges Boone with the vital task of finding a new refuge for the Nightbreed, endowing him with the name "Cabal." As Boone departs Midian alongside Lori, the remaining Nightbreed congregate at a dilapidated barn. Boone promises Narcisse he won't forget them and will locate a sanctuary for their kind.
In an alternate ending, seen in the special "Cabal Cut," the Nightbreed await Boone's return in a barn. As he bids farewell to Lori—who fears aging while he remains unchanged—she stabs herself in a desperate bid to be with him eternally. After a tense moment of silence, Boone succeeds in resurrecting her as a Nightbreed. Meanwhile, Captain Eigerman stumbles across the transformed Ashberry underground, rejoining the fray with vengeance in his heart as he embarks on a vendetta against the Nightbreed.
