In 1975, a sinister hippie cult called Unity Fields commits mass suicide in a horrific manner - by fire - at the behest of its psychopathic leader, Franklin Harris (Richard Lynch). Only one young woman named Cynthia (Jennifer Rubin) survives to tell the tale. Now, 13 years later, Cynthia is having grim reminders of the mass suicide, as people around her begin to die one at a time. Cynthia finds out quickly that the ghost of Harris is back to claim his 'love child'.
The story follows five contestants who agree to take part in a reality webcast. The rules are simple: "Spend 6 months in a house for $1 MILLION. If someone leaves, everyone loses!" With the end of the 6 months nearing, the tension between contestants Matt (Sean Cw Johnson), Emma (Laura Regan), Charlie (Jennifer Sky), Danny (Stephen O'Reilly) and Rex (Kris Lemche) is at a high level. Instead of their regular food deliveries, packages containing sinister object arrive. A letter stating that Danny's grandfather has died, a gun with 5 bullets and a bottle of champagne.
A group of twenty high school students partake an elite class gearing them for the college exam. Among them are the rebellious Kang I-na, her timid best friend, Yoon Myong-heo, and the class joker, Kang Hyun, who harbors an affection for I-na. After several strange incidents in which I-na is almost strangled by Cho Beom, forcing him to be taken to a mental facility, and a student being throttled in the restroom, the class is interrupted by a TV showing of the top-ranking student, Min Hye-yeong, being trapped in a glass tank that is slowly filled with water. A voice announces that he will pose questions to the class; should they fail to answer them in a given amount of time, they will all be kidnapped and killed one by one, exemplified when they realized that some of the students have fail to attend the class. Also, the security system have been disabled and should any one them and their two teachers, Hwang Chang-wook and Choi So-yeong, attempt to leave the school, they will be killed nonetheless. Despite their panicked attempts, the class fail to save Hye-yeong.
Bill Chrushank (Jeff Fahey) is a psychologist working with convicted killers at a prison in addition to teaching classes at a university. Ray, a convict who murdered his cellmate recently, tells Bill he can’t do anything to fix him. At home, Bill wonders to his wife (Kim Delaney) if this is true. He wants to be able to fix someone like Ray but in all his research and studies has never seen proof it’s possible. The next day, while driving to work, Bill gets in a horrific car accident where he loses his arm. At the hospital, Dr. Agatha Webb (Lindsay Duncan) convinces Bill’s wife to sign off on an experimental transplant surgery to give him a new arm from a donor they have waiting. Heavily drugged, Bill is wheeled into the operating room where he groggily notes several armed cops in hospital scrubs. The cops leave as soon as Dr. Webb removes the unknown donor’s head from his body at a nearby operating table. Bill awakens from the surgery and struggles to rehabilitate his new arm, which is covered in gruesome scars. One day, while struggling to lift a tiny weight, his arm makes a violent unexpected move upward. After this happens Bill makes a swift recovery and is released from the hospital. After some initial awkwardness between his wife with the new arm, he pleasures her with it and they make love. Just when it seems things are back to normal, Bill starts seeing flashes of horrible acts of murder (as if he is committing them). Next, he loses control of his new arm and cuts his face while shaving. Then at the prison, Ray freaks out seeing that Bill has the same tattoo on his wrist, which is only given to inmates on death row. Bill has a police friend scan his new fingerprints and is shocked to discover the arm came from convicted serial killer Charley Fletcher (John Walsh), who had murdered 20 people.
The Warlock (Sands) is taken captive in Boston, Massachusetts in 1691 by the witch-hunter Giles Redferne (Grant). He is sentenced to death for his activities, including the bewitching of Redferne's bride-to-be, but before the execution Satan appears and propels the Warlock forward in time to 20th century Los Angeles, California. Redferne follows through the portal.
Reality show contestant Kimberly is driving through the West Virginia back country searching for the location of her next project. While driving, she accidentally hits a teenager. She stops to check on him, but the teenager is revealed to be Brother, a cannibal, who bites her lips off. She attempts to escape, but runs into Three Finger, who splits her in half vertically with an axe. He and Brother drag her halves away.
In the town of Moorehigh in 1957, the patients of Dr. Evan Rendell kept disappearing. After some investigation, the citizens of Moorehigh found that he and his son Evan, Jr. (nicknamed "Dr. Giggles" for his hideous laugh), were ripping out patients' hearts—in an attempt to bring back the doctor's dead wife. The townspeople stone Dr. Rendell to death...but Evan, Jr. disappeared.
Dr. Dan Potter is the replacement for Dr. Harry Merton, a psychiatrist at Dr. Leo Bain's psychiatric haven. Dr. Bain operates the haven through very lenient methods. The 3rd floor patients (paranoid former POW Frank Hawkes, pyromaniac preacher Byron Sutcliff, obese child molester Ronald Elster, and homicidal maniac John "Bleeder" Skaggs) initially treat Dr. Potter with mixed hostility.
The film takes place in 1986, 13 years after the events of the first film. It begins with Buzz and Rick, two rowdy high school seniors racing along an abandoned stretch of Texas highway, en route to a weekend of fun in Dallas. They are heavily intoxicated and use their car phone to call and harass on-air radio DJ Vanita "Stretch" Brock (Caroline Williams). Unable to convince them to hang up, Stretch is forced to keep the line open. Buzz and Rick encounter a large pickup truck which runs parallel to them on a remote bridge. Suddenly, Leatherface (Bill Johnson), wielding a chainsaw, emerges from the back of the truck and proceeds to attack Buzz and Rick. After a short struggle, Rick tries to shoot Leatherface with a .44 Magnum revolver, but misses his target. Leatherface then slices off part of the driving Buzz's head, and the car ends up crashing and killing Rick.
At a college pre-med student fraternity New Year's Eve party, a reluctant Alana Maxwell is coerced into participating in a prank: she lures the shy and awkward pledge Kenny Hampson into a darkened room on the promise of a sexual liaison. However some other students have placed a woman's corpse in the bed. Kenny is traumatised by the prank and is sent to a psychiatric hospital.
Four college students, unable to find on-campus housing, take up residence in Mrs Engels's (De Carlo) hilltop mansion, where she lives with her strange son, Mason (Reardon), and her daughter, Victoria (Steele), whom Mrs Engels secretly keeps hidden in the attic, a botched lobotomy having left her mute and homicidal. After one of the students is found dead, a police investigation is launched, which uncovers the history of the mansion and its owners, as the remaining students become endangered.
A masked intruder attacks Amy as she showers (resembling the famous shower scene from Psycho). The "attacker" turns out to be her younger brother Joey, a horror movie buff, and his "weapon" is merely a realistic-looking plastic knife. He has played the first of several practical jokes on her.
In 1979, Jimmy Bones (Snoop Dogg) is a numbers runner who is respected and loved in his neighborhood as its respected member and protector. When he is betrayed and brutally murdered by corrupt white cop Lupovich (Michael T. Weiss) and drug pusher Eddie Mack (Ricky Harris), Bones' elegant brownstone building becomes his own tomb, and is closed.
Nicole Barlow is finalizing preparations for her mother's funeral at her childhood home in San Pedro, California. Her sister, Annie does not want to attend, reminding Nicole of the way their mother used to treat them. Nicole tries to contact her cousin, Liz and her daughter Eva via video call. After losing the connection, Nicole sees an open door, leading into a dark room and walks inside.
The film begins with a woman wearing a hospital gown, whispering to herself. Her back is revealed, showing sutures from injuries all over her back. The scene cuts to a woman who runs from something unknown to a road near a forest. She stops a car, screaming, begging for help, when her hand is revealed, covered in blood from a wound on her stomach.