The story continues from chapter 1 after Charlie finds a two dead bodies, with springlock wounds, one of them looking like her which leads her to suspect the animatronics are searching for her. Later when Charlie is exploring her fathers house with John, she gets attacked by twisted foxy who is now a fleshy abomination, but when John defeats him, he becomes a animatronic again which they then discover the illusion discs, which changes the animatronics appearance to the human brain and eye hence why the book states ”don’t trust your eyes.”
“It’s not like the other mascots from Freddy’s. These aren’t made of fur and fabric, they’re made of us—by twisting our minds. You shot the chip. You killed the illusion.”
they release three high pitched sound waves, which cannot be heard but instead affect the brain by never having a pattern, as right as the brain is about to see a pattern the frequency changes.
”In order for you to function in the world, your mind fills in the spaces of that tree with its own leaves and branches.”
this is why the animatronics look friendly with the illusion discs to most people, but fleshy abominations to those who know about the truth.
Later on, William Afton now Springtrap lures Charlie into the abandoned pizzaria, where they soon enter a ”cave” which turns out to be a illusion as the regular animatronics fight off the twisted ones. Soon after, Charlie is caught by twisted freddy and stuffed inside the suit where she is then crushed and mangled by the springlocks and dies. At the end of the book ”Charlie” suddenly appears at the front door, with Clay, Jessica, John still shocked about what happened, but then john says.
”That’s not Charlie.”