Previously in Five Nights at Freddy's:

Freddy and his friends were torn out of their own reality and thrown into an adventure world. Their purpose was to save it from utter destruction, and with the help of special powers they achieved, they were able to battle their way through all sorts of enemies and take down the force threatening to destroy what he had created.

After this, someone known as Desk Man warned Freddy that something terrible was coming, and then several of the party members went missing. Freddy and his friends went on a mission to rescue them from an evil rainbow that was holding them prisoner within ripoffs of games. Once they conquered the rainbow, Desk Man told Freddy that he had made something horrible, stating that her name was "Baby". The lights went out, and when Freddy saw Desk Man again...

... he was dead.

Prologue

The lights came on, illuminating the stage in Ballora Gallery.

"It looks like Ballora isn't on her stage," came the voice of the HandUnit. "Let's give her a controlled shock."

A bright flash of light flared and a loud buzzing zap filled the air. Ballora cried out and a loud clanking sound was heard as she collapsed.

"She still isn't onstage," said HandUnit. "Let's shock her again."

Circus Baby sighed, shutting her eyes, trying to shut out the tortured cries from Ballora as that terrible electrical current ran through her again and again. She wished there was something that could be done about this.

Ballora had found a way, but it wasn't pleasant. Every night, someone named William Afton would come to Afton Robotics Incorporated to watch the place at night, and then she would try to kill him. Baby didn't like this method at all; everything about it seemed wrong, and potentially evil. And worse yet, William somehow knew that Ballora was doing it. He electrocuted her, not only to get her back on stage should she leave it, but also as a means of punishment. Baby knew that he thought that she was in on it, too, so he would electrocute her as well.

I'm innocent, Baby thought sadly. This shouldn't be happening to us. Ballora's just blind - not only literally, but figuratively with rage. She doesn't know what she's doing, she's not thinking straight. Don't blame us for these crimes being committed. Don't punish us for what Ballora does during the night. Just... please...

Baby said this final line out loud, in a whispering, trembling voice filled with fear.

"Don't hold it against us."