For seventeen years, the town of Haddonfield, Illinois has been haunted by a night when evil roamed the street. Everyone knows his name. Now, everyone will know the truth!

It's now six years since the last Halloween celebration in Haddonfield. Michael Myers, his niece Jamie, and the mysterious Man in Black all disappeared after the explosive end of Part 5. Everyone assumes them all to be dead...but actually, Jamie has been captured by the Man In Black, who has her impregnated. The baby arrives on Halloween eve, and a kind woman named Mary helps Jamie and her baby escape. However, MichaelMyers is close behind her, and Jamie dies shortly into the movie, gutted with farm machinery.

Meanwhile, Tommy Doyle (the child Laurie Strode sat for in the first film) has his eye on a family who's moved into the old Myers house. Tommy has become obsessed with Michael Myers. After hearing Jamie screaming for help on a radio show, Tommy finds her baby and hides him. The people living in the Myers' house are relatives of Laurie Strode...included is Kara Strode, and her illegitimate son, Danny - who "hears the voice" that Michael heard. Michael stalks each of the Strodes, trying to get to Jamie's baby. Across the street, Tommy reveals that Michael has been cursed with Thorn, where a young man must wipe out his entire family for the good of civilization. The plot takes a turn when the Man in Black reveals himself to be a major character. He has been experimenting with pure evil all these years...and kept it all secret at the Smith's Grove sanitarium. Tommy and Dr. Loomis follow this madman to the sanitarium, where an all-out battle occurs with Michael. It is revealed that some form of genetic research has been happening at Smith's Grove, with test tubes and DNA charts lying around. The film concludes with everyone getting out safe, except for Loomis, who walks back inside to "take care of unfinished business."