Halloween II is a 1981 horror film directed by Rick Rosenthal, and written and produced by John Carpenter and Debra Hill.
It's the second installment in the Halloween series and is a direct sequel to Carpenter's Halloween, immediately picking up where it had left off, set on the same night of October 31, 1978 as the seemingly unkillable Michael Myers continues to follow Laurie Strode (Jamie Lee Curtis) to a nearby hospital while Dr. Sam Loomis (Donald Pleasence) is still in pursuit of his patient.
On October 31, 1978, Laurie Strode (Jamie Lee Curtis) is sent to the hospital due to the injuries inflicted by Michael Myers (Dick Warlock) while Dr. Sam Loomis (Donald Pleasence) attempts to track him down, vanishing after being shot six times and falling from a second story balcony.
Meanwhile, Michael steals a butcher knife from a house and kills a girl named Alice (Anne Bruner) who lives next door as he seeks shelter to recover from his injuries.
He later learns of Laurie's location from a radio broadcast and makes his way to Haddonfield Memorial hospital.
Laurie begins having flashbacks of being adopted by the Strodes and visiting a young boy in a mental institution.
Her sedation leaving her in a semi-conscious state most of the time and her friend Jimmy Lloyd (Lance Guest) begins to worry about her, developing romantic feelings for her despite the chagrin of Mrs. Alves (Gloria Gifford), the head nurse, who is trying to keep her resting comfortably.
Dr. Loomis and Sheriff Brackett (Charles Cyphers) continue to search for Michael, only for an oncoming speeding police car to accidentally hit and kill Ben Tramer (who was dressed for Halloween wearing a mask similar to Michael's and was Laurie's crush in the first movie) in the process.
Michael cuts the phone lines. He kills security guard Mr. Garrett (Cliff Emmich) with a claw hammer, strangles ambulance driver Budd Scarlotti (Leo Rossi), and drowns nurse Karen Bailey (Pamela Susan Shoop) in a scalding hot tub.
Orderly Janet Marshall (Ana Alicia) notices that Laurie is strangely reacting to her pills, and goes to tell the main attendant of the hospital, Dr. Frederick Mixter (Ford Rainey).
She rushes through his office, only to find his corpse with a needle sticking out of his eye. Before she can run away, Michael appears behind her and murders her as well by injecting air into her temple. Laurie attempts to flee before Michael can find her.
Meanwhile, Dr. Loomis follows clues connecting Michael to Samhain and the occult which might explain his seeming indestructibility, but he is interrupted by a visit from his nurse colleague Marion Chambers (Nancy Stephens) from the mental institution who says she had been ordered to take him back under the enforcement of a US Marshal.
En route, she tells Loomis that Laurie Strode is Michael Myers's younger sister and Loomis realizes that she is his target before Loomis forcibly orders the Marshal (John Zenda) to turn around after firing a warning shot.
While searching around the hospital, Jimmy eventually discovers Mrs. Alves strapped to a table in one of the surgery rooms, her blood drained. While trying to hurry out of the room, Jimmy slips, falls, and gets a concussion which renders him unconscious.
Meanwhile nurse Jill Franco (Tawny Moyer) finds a sedated Laurie walking around and is killed when Michael stabs her in the back with a scalpel.
Laurie manages to barely escape Michael by going through the boiler room and up to the parking lot outside, discovering Mr. Garrett's body along the way.
She is unable to start any cars and also notices that all of the tires have been flattened, presumably by Michael who had earlier overheard her and Jimmy discussing one of them driving to the police department to get help.
Jimmy eventually makes it out of the hospital and out to his car to seek help, but faints and falls unconscious again from the earlier massive concussion while trying to start his car as he and Laurie attempt to escape the hospital.
Dr. Loomis, Marion and the Marshal arrive and just barely save Laurie from being killed by Michael. Marion goes to the police car to call for help, Michael cuts the Marshal's throat, and Loomis and Laurie flee into the operating rooms.
Michael stabs Loomis in the stomach, wounding him, and Laurie shoots out both Michael's eyes, causing him to blindly swing at them.
Loomis fills the room with ether and oxygen gas using the distraction to allow Laurie to escape. Then he ignites it, blowing up the surgery room in the process and evidently immolating them both in the fire.
At daybreak, Laurie is loaded onto an ambulance, having visions of Michael's burning body as she is driven off to safety.
In the alternate ending, shot for US TV, she sees a familiar shape sit up on the stretcher beside her in the ambulance, which turns out to be Jimmy. The two hold hands and Laurie proclaims "We made it!"