After being impaled by a pipe and plunging into a river at the end of the previous film, the undead Maniac Cop Officer Matthew Cordell acquires a junked police cruiser and continues his killing spree through New York City. Finding a convenience store in the middle of a robbery, he kills the clerk; the thief is subsequently killed in a shootout with police. As Cordell stalks the streets, his enemies Officers Jack Forrest and Theresa Mallory are put back on duty by Deputy Commissioner Edward Doyle, who has the two undergo a psychiatric evaluation under Officer Susan Riley. While Jack is content that Cordell is long gone and wants to go on with his life, Theresa is convinced that Cordell is still alive and plotting his revenge.
Second-hand bookstore clerk Virginia Clayton (Jenny Wright) becomes absorbed in the book ‘I, Madman’ by Malcolm Brand (Randall William Cook). In the book, the deranged, deformed Dr. Kessler is obsessed with beautiful actress Anna Templar and kills victims, sewing part of each victim’s face onto his own. But as Virginia continues to read, someone starts to emulate the killings in the book, targeting the people around her.
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.
Seven sorority sisters pull a prank on their strict house mother, Mrs. Slater, who is known for carrying a sharp walking cane. Their plan is to put her cane out in their dirty pool and force her at gunpoint to retrieve it. The prank goes awry when Vicki, believing the gun to be loaded with blanks, shoots Slater who collapses and appears to be dead. The girls agree to hide the body in the pool until their graduation party is finished.
College film student and aspiring film writer Maggie Butler (Jill Schoelen) has been having recurring dreams of a young girl named Sarah who is caught in a fire and being chased by a strange man who is trying to kill her. She records what she remembers on an audio tape and plans on making the story into a film. Maggie lives with her mother Suzanne (Dee Wallace Stone), who has been receiving strange, demonic prank calls recently. On her way to class, a boy she has been seeing named Mark (Derek Rydall) embraces her and tries to get her go to his place. Maggie shuns his advances, explaining that she can't be distracted from writing her script.
On Halloween in 1999, young Michael Myers donned a clown mask and stabbed his older sister Judith (who had just had sex with her boyfriend) to death in their suburban home in Haddonfield, Illinois. Michael was sent to an asylum in the nearby Bellevue, and placed under the care of Doctor Samuel Loomis. On the fifteenth anniversary of Judith's death, Michael escapes by hijacking one of the institution's vehicles, returns to his old home, and spies on Laurie Strode as she drops off the house's keys at the behest of her realtor father.
Michael Myers has been in a coma for ten years since the explosion at Haddonfield Memorial Hospital and is being transferred to Smith's Grove Sanitarium by ambulance. Upon hearing that he has a niece, Michael awakens, kills the paramedics, and makes his way to Haddonfield to look for her. Dr. Sam Loomis (Donald Pleasence), Michael's former psychiatrist, who also survived the explosion, learns of Michael's escape and gives chase. He follows Michael to a small gas station and eatery, where Loomis finds Michael has killed a mechanic for his clothes, along with a clerk. Michael then escapes in a tow truck and causes an explosion, destroying Loomis's car in the process. Loomis is forced to catch a ride to Haddonfield to renew his search for Michael.
In 1939, a woman dies while giving birth in a slaughterhouse, and the manager disposes the baby in a dumpster. A young woman, Luda Mae Hewitt (Marietta Marich), finds the child while searching for food. She takes him back to the Hewitt residence, names him Thomas, and decides to raise him as her own.
Twenty years after the events of Halloween and Halloween II, on October 29, 1998, Marion Chambers (Nancy Stephens), Dr. Sam Loomis' former colleague, returns to her house in Langdon, Illinois, to find it has been burglarized. Her teenage neighbor Jimmy (Joseph Gordon-Levitt) searches the house and finds nothing. While waiting for the police in her house, Marion discovers a file is missing, the one on Laurie Strode (Jamie Lee Curtis), Michael Myers' sister who escaped the attacks two decades earlier. She also realizes that someone has been in her house and immediately rushes back over to Jimmy's house, where she finds him and his friend dead. Michael Myers (Chris Durand) appears, and attacks Marion before slitting her throat, killing her. The police arrive as Michael leaves the house with Laurie's file.
On July 4, 1996, four high-school seniors - Julie, her boyfriend Ray, Julie's best friend Helen, and her boyfriend Barry - drive to an isolated beach after drinking at a party. While driving home, Ray becomes distracted and accidentally hits a pedestrian, apparently killing him.
Cynthia is traumatised by the death of her baby after leaving him in a bathtub, where he accidentally drowned. She and five of her friends, Jeff, Rob, Lynn, Paul and Terri decide to go on a vacation. They take a plane somewhere, but are plagued by engine troubles and are forced to land the plane on a lonely deserted island. The six set camp and the next morning, Paul stays at the camp while the others set off to find help. They come upon a large cottage nestled in the woods.
In 1971, on a visit to his institutionalized grandfather, who warned 5-year-old Billy Chapman that Santa Claus punishes the naughty, his family happens to come across a man in a Santa Claus outfit seemingly having car trouble. The man - actually a criminal who has just used that disguise to rob a liquor store after he kills a man and escaped - pulls a gun and mercilessly kills Billy's father in front of him and his infant brother Ricky, then slits their mother's throat with a switch blade, leaving the children alive. Three years later, Billy and Ricky are celebrating Christmas in an orphanage run by Mother Superior, a strict disciplinarian, who persistently strikes children who misbehave and considers punishment for their wicked actions as a good thing. Sister Margaret seems to be the only one who sympathizes with the children, trying to get Billy to open up and play with the children, but they are constantly under Superior's scrutinizing eye and they regularly end up getting punished.
Todd and Terry are twins. They are blonde, cute, bright and identical in every respect, with one exception. One of them is a murderer. This starts one night at a drive-in theater when a teenager was slaughtered in the back seat of his car while his girlfriend watched. Todd is found guilty for the heinous crime and is locked away in an asylum.
Based on the true story of Lizzie Borden, a Sunday School teacher who lived with her father Andrew, her stepmother Abby, and her older sister Emma in a small house in Fall River, Massachusetts, the film depicts a hot summer day in August 1892 in the Borden home where Lizzie comes across the grisly murder scene of her father who was brutally killed with a hatchet. After local law enforcement responds to the scene, the body of Abby Borden is discovered upstairs, also killed with an ax. As the case progresses, the evidence gathered by the authorities seems to point to Lizzie as their prime suspect. Lizzie's lawyer Andrew Jennings, however, maintains that a woman could not commit such a cruel act; arguing it is far too gruesome a crime for any woman to commit. Regardless, Lizzie is put on trial for the murders and the courtroom case makes headlines in newspapers throughout the country. Newspaper accounts state the crime to be the most infamous of the century. Eventually, the jury finds Lizzie innocent of all charges. The film ends with a fight between Emma and Lizzie, in which Lizzie asks Emma if she wanted know the truth. Lizzie then whispers inaudibly into Emma's ear while a series of flashbacks are shown in which Lizzie murders their stepmother and father. It is heavily implied that Lizzie Borden was in fact their murderer, and a visibly upset Emma leaves the room. Lizzie walks outside and hears three children jump roping to the famous nursery rhyme: "Lizzie Borden took an ax/ And gave her mother forty wacks/ And when she saw what she had done/ She gave her father forty-one." Emma is then shown leaving the house, never to return.