So, as you probably know, the trailer for the third game in the Fnac series came out a few days ago, and I think i've peiced it all together. Here is my theory.
In Fnac 2, once you have obtained all 4 stars, you can click on the fourth, revealing a secret minigame. You play as a young girl, and as you head to the room on the left, you can see RAT and CAT on a stage. This could be the first Candy's establishment. What happens next is that a boy nears RAT. RAT then bends down to him, and smacks the boy as the minigame ends. We dont know who this boy is, but we can assume that he is the brother of the girl you play as. The girl also is crying, possibly because her brother is getting to close. My theory is that Fnac 3 is a dream. You might think im only saying this because Fnaf 4 was a dream. Well, much like Fnaf 4, what are the chances of nightmare robots invading your house trying to kill you? In the teasers and the trailer, you happen to be in a girls room, indicating that it just MIGHT be the dream of the girl we play as in the Fnac 2 minigame. Also, in the second teaser, or was it the third? Idk no ones counting. But whatever. If you brighten the image up, you see RAT at the doorway, as well as the words 1962 above. I think thats the year the incident happened. In the fnac 2 minigame, it does look quite old fashioned, as well as some old sounding music.
So, here is how i think the complete story of this game goes. The first thing that happens that we know of, is the boy being attacked by RAT. Due to the incident, it closes down, and a new Candy's opens, featuring Candy and Blank, as shown in the other Fnac 2 minigames. The boy's sister, was scared to death, and had many nightmares about RAT and CAT, the culprits of the incident.
So yeah. Thats my theory. I hope you agree with it