Okay so I have been crawling around for hours without killing any guards (which is easy as my sneak is crazy high) but I can't seem to find a way to open the damn gate to where the room lies behind. The room that supposedly holds the researcher's work to unlock the Falmer language. Where is this key or is there something I'm missing? I've wrecked my poor char's lungs by walking through the toxic hallway pushing some tiles on the floor hoping some door will be opened but nothing happens.

I'm now going back to pickpocket the geezer again and hopefully there's another key there but I only recall him having one.