The Mind-Wiped Doll Game Over is an ending which occurs when stealing Alice's panties prior to recruiting her to your team.
First you would have to have gotten to the crystal in the Bee Hive in order to trigger the event for the silver key to drop. You require the key to access Alice's room in order to gain access to her panties.
After triggering the Medical Exam event, you can access Alice's room and retrieve her panties and continue the event as you see fit to continue. That means even if you decide not to drink the potion and stay with Marianne to get through the event it will still trigger for taking her panties.
She meets you right outside your door and tells you that she knows you took her panties. She then uses Macabre Puppetry to find out why you stole them. However due to the inability to talk about Wendy, she decides continue to use Macabre Puppetry to enslave you even more, in which you become one of her dolls. She eventually realizes her plans to enslave the entire camp because you weren't able to stop her.