I believe this fic is a Criminal Minds crossover, but it may have been NCIS. Sometime after the season 7 finale, the crossover law enforcement agency is looking into the destruction of Dick Roman's business empire and find the drugs that were intended to sedate the human public via Biggerson's. They come to the conclusion that some sort of terrorist plot had been foiled, and I believe that they discovered that the real Dick Roman had been killed months prior and impersonated in order to further this plot. They believe that the Leviathans were terrorists using some sort of 3D-printed masks made of an unseen-before material, and that the shapeshifters that the Winchesters stopped in "Skin" and "Nightshifter" were actually test-runs for the terrorist group's 3D-printed masks. Crossover-LEOs want to interview Sam 'n Dean (and possibly other hunters, I don't recall) about Dick Roman, as the boys' "religious beliefs" in shapeshifters, Leviathan, etc., allowed them to realize that the "terrorists" were impersonators, causing the terrorists to impersonate them in order to discredit them and stop them from interfering. I don't remember whether the crossover characters come to realize that monsters are real.

Thanks in advance!

Pretty much what it says in the title c;
Thanks in advance to anyone who can find this fic for me! :)

other info:

> cas was tortured by leviathans that made themselves look like dean

> cas thought dean was a leviathan when he first saw him

> he threatened him with a knife until dean convinced him that he was himself

> dean got into the building easy because every leviathan thought he was just disguised as dean to torture cas

> i think dean hasn't told bobby or sam that he went to kill roman

And that's all i know sorry ^_^

So, I really loved the Leviathan -- I thought they were some of the best fictional antagonists I've ever seen (Dick Roman in particular). I'm looking for anything and everything about them -- Purgatory!fic would be awesome, as would be some nice angsty/dubcon Levi!stiel/Dean, but seriously, anything is good.

(Mods, there doesn't seem to be a creature: leviathan or character: dick roman tag, so I'm leaving it at creature: not human, and seasons 7 & 8.)