So in my AU (alternate universe) there are two worlds. In one world, there is the animatronics, and where the murders happened. That's where JJ's Tale is set. But then in the other world, there is each of the animatronics in humanoid form. That's where Foxy's Tale is set. When the murders took place, the humanoid world was created, and the animatronics alternate selves appeared, with no memories.
The Marionette was the only one who knew, and he'd been the one to create that world. He put the children in the suits, and cast a spell that brought them to life, while also giving them a second chance at a human life. He then duplicated himself as a human, but in the original world, and then implanted everything he would need in his human life into his mind, before sending the duplicate through to the other world. The others were simply left to find out their own lives.
If that doesn't make sense, just tell me and I'll answer any questions you have.
