Hogwarts reads the seventh horcrux, made by Emerald Ashes

I think, I suppose (I don't remember) Umbridge finds the books and obviously believes they're real, but after the first few chapters it becomes clear to everyone except her, and to the people she presumably invited to read them, that the diary is fake, possibly; I don't remember. Also, I'm looking for fanfiction of this kind; someone from Hogwarts reads metafiction and reacts to it. Can you help me find them?