The finale in which Frank has to evade Patricia, who's armed with a shotgun as he constantly shifts between the present and the past hospital, bearing witness to the horrible massacre that happened many years ago, often from the perspective of the people being slaughtered.
"I'm in the mood for vivisection!" "Me too! Me too!" (they're referring to vivisection with a pick ax!)
The And I Must Scream implications of a spirit missing both chances to move on. You are stuck in this plane of existence until you just fall apart. The Judge has been around for quite a while, and showed no signs he was about to give up the ghost anytime soon. And if no one around has had near-death trauma, then the only people who can hear you are other ghosts, who are equally stranded.