Purple Death (FNAF Fanfiction)

Alice has now turned 5 years old, and she has her birthday over at
Freddy's Pizzeria. The security guard Vincent is on watch on that day. As Alice is looking around for the bathroom she hears a few screams. But from a closet. Alice decides to look but what she see's is frightful for her to even forget from her mind. Now 10 years later, Alice has fully grown and works with people who kill others, after her shift she hears children calling her name from the new attraction, but something about it scares her to remember the fearful day. What was it that scared her that Day?
Who was the one who caused it?
Find out in my fanfiction FNAF 1,2,3