Halloween II is a 1981 American slasher film directed by Rick Rosenthal in his directorial debut, written and produced by John Carpenter and Debra Hill, and starring Jamie Lee Curtis and Donald Pleasence who reprise their respective roles as Laurie Strode and Dr. Sam Loomis. It is the second installment in the Halloween film series and serves as a direct sequel to Halloween (1978). The plot picks up directly after the first film, with Michael Myers following survivor Laurie Strode to the local hospital, while his psychiatrist Dr. Loomis continues his pursuit of him.
Though Carpenter and Hill co-wrote the screenplay to the sequel, Carpenter was reluctant to extend his involvement and mostly refused to direct, instead appointing the direction to Rosenthal. Stylistically, Halloween II reproduces certain key elements that made the original Halloween a success, such as first-person camera perspectives, and the film picks up right at the end of the cliffhanger ending of the original film and was intended to finish the story of Michael Myers and Laurie Strode. It also introduces the plot twist of Laurie Strode being the sister of Michael Myers, a feature that would form the narrative arc of the series in subsequent films, including Rob Zombie's remake and its sequel, but was dropped from the 2018 film trilogy. Filming took place in the spring of 1981, primarily at Morningside Hospital in Los Angeles, California, on a budget of $2.5 million.
Halloween II was distributed by Universal Pictures, and premiered in the United States on October 30, 1981. The film was a box office success, grossing over $25 million domestically, though it received mixed reviews, with praise for its performances and atmosphere, but drew significant attention from film critics who criticized its overt violence and gore compared to the original film. Originally, Halloween II was intended to be the last chapter of the Halloween series to revolve around Michael Myers and the town of Haddonfield, but after the lackluster reaction to Halloween III: Season of the Witch (1982), Michael Myers was brought back six years later in Halloween 4: The Return of Michael Myers (1988).
On October 31, 1978, Michael Myers is shot by his psychiatrist Dr. Sam Loomis and falls off a balcony. He survives and escapes into the night. Wandering the alleys, he steals a kitchen knife from an elderly couple and kills the teenage girl next door. Meanwhile, Laurie Strode, who narrowly avoided being killed that night, is taken to Haddonfield Memorial Hospital while Loomis continues his pursuit of Michael, accompanied by Sheriff Leigh Brackett. Loomis mistakes costumed teenager Ben Tramer for Michael, resulting in Ben being hit by a police car and burning to death. Upon learning his daughter Annie has been killed by Michael, Sheriff Brackett blames Loomis and abandons the search, leaving Deputy Gary Hunt to take his place.
At the hospital, paramedic Jimmy begins to fall in love with Laurie, but head nurse Virginia Alves limits the time he spends with her. After hearing a news broadcast revealing Laurie's location, Michael makes his way to the hospital, where he cuts the phone lines and disables the cars. Wandering the halls in search of Laurie, he kills the security guard, the doctor, and several nurses throughout the night. In her hospital room, Laurie dreams about the time she learned she was adopted, and remembers she once visited a young Michael at the sanitarium. Jimmy Howell and nurse Jill Franco search the hospital for Laurie, who is trying to evade Michael.
Jimmy finds the body of Mrs. Alves before slipping in a pool of her blood and knocking himself unconscious, giving himself a concussion. Meanwhile, Loomis is informed that Michael broke into the local elementary school earlier. He discovers clues connecting Michael to Samhain and the occult, which might explain his apparent indestructibility. His colleague Marion Chambers arrives to escort him back to Smith's Grove on the governor's orders and under the enforcement of a US Marshal. On the way, she tells him that Laurie is Michael's younger sister; she was put up for adoption after the death of Michael's parents, with the records sealed to protect the family.
Realizing that Michael is after Laurie and being told she was brought to Haddonfield Memorial Hospital, Loomis forces the Marshal at gunpoint to drive back to Haddonfield. Jill finally finds Laurie, only to be killed by Michael, who then pursues Laurie through the hospital. She manages to escape to the parking lot and hides in a car. Jimmy soon arrives and tries to drive the car to safety, but passes out again on the horn, alerting Michael. Loomis, Marion, and the Marshal reach the hospital just in time to save Laurie. Loomis shoots Michael until he falls down, seemingly dead. While Marion calls the police, the Marshal tries to check Michael's pulse as Loomis warns him to stay away, knowing he isn't dead. Michael then reawakens and slits the Marshal’s throat with a scalpel.
Loomis and Laurie run into an operating room, where he gives her the Marshal's gun before being stabbed by Michael. Laurie shoots Michael in both eyes, blinding him. As he staggers around trying to find them, the two fill the room with flammable gas. Loomis orders Laurie to run before igniting the gas, immolating himself and Michael in an explosion. Laurie watches as Michael, engulfed in flames, emerges from the fire before finally collapsing. The next morning, she is transferred to another hospital, traumatized but alive.