Marlon Bain's letters to Steeply
I cannot help you too much with the facts surrounding Dr. Incandenza’s suicide. I know that he erased his own cartography in a grisly way. I was told that in the year leading up to his death Dr. Incandenza was abusing ethyl alcohol on a daily basis and was working on a whole new genre of film-cartridge that Orin at the time claimed was driving Dr. Inc insane.
Context
Marlon Bain on JOI's death: "erased his own cartography" is the eliminate-your-own-map idiom in its most baroque dress, applied to the map idiom's own household — and Bain's secondhand facts tie the suicide to the samizdat exactly where the wraith's p. 839 confession does, from the outside.