The police discover Michael's location and surround the shed. Loomis arrives and goes into the shed to try to reason Michael into letting Laurie go. Inside, he has to inform Laurie, who believes that the younger Michael is holding her down, that no one is restraining her and that she must maintain her sanity. Just then, Deborah instructs the older Michael that it is time to go home, and Michael grabs Loomis and begins repeatedly slashing his face and stabbing him in the chest. Stepping in front of a window while holding Loomis's body, Michael is shot twice by Sheriff Brackett and falls onto the spikes of some farming equipment. Apparently released of the visions, Laurie walks over and tells Michael she loves him, then she stabs him repeatedly in the chest and finally in the face. The shed door opens and Laurie walks out, wearing Michael's mask. As she pulls the mask off, Laurie transitions to isolation in a psychiatric ward, grinning as a vision of Deborah dressed in white stands with a white horse at the end of her room.

Laurie was the killer? If so there is no way she was able to do all of the killing as she would have had to clone herself. Also, was Laurie supposedly dead at the end of the DC, or was it just sloppy moviemaking that didn't explain she was still alive?

Zombie fucked up by trying to go the supernatural route, Michael was real because Loomis acknowledged him a the end. Laurie was seemingly being held down by young Michael but it was all in her head....Loomis even shouts those exact words to her when she's screaming.

The white horse bullshit at the end could have many meanings but none at all that would link laurie to being the killer. Again, it was a huge failure at trying to add a supernatural element to the movie - it was very poorly done and just didn't make any sense.