Twenty years after surviving a horrific ordeal on Halloween night, Laurie Strode lives under an assumed name as the headmistress of a secluded private school in Northern California. Traumatized by her past and the brutal attacks by her brother, Michael Myers, Laurie has faked her own death to escape her history. Despite her new identity and a seemingly normal life, Laurie is still haunted by nightmares and remains on edge, particularly as Halloween approaches. She maintains a strained relationship with her teenage son, John, who struggles under the weight of his mother's fears and her overprotective nature.

As Halloween rolls around, Laurie's worst fears resurface when Michael Myers returns, intent on finishing what he started two decades earlier. The secluded school becomes a battleground as Laurie must confront her long-feared nemesis. Unaware of the danger, John and his friends view the Halloween lockdown of the campus as an opportunity to have their own celebration, unknowingly making themselves targets. Laurie must now summon all her strength and courage to protect her son and his friends, facing the embodiment of her nightmares head-on in a final confrontation with her twisted brother.