A nurse is raped, she claims, my an invisible horny old dude. Right off the bat, it's funny and disturbing. The X-files team investigates the old folks homes which kicks off a series of geezers kicking the bucket. Dark tones crammed into a claustrophobic, spooky setting reminded me of John Carpenter and Nightmare On Elm Street: The Dream Warriors.
The story nicely develops the traditional "haunted house" story by combining elements of alternative medicine and shamanism. Excelsis Dei seems to continue on the last episode's concern of using experimental substances on people; though, whereas the last episode is more science- fiction, this episode takes the paranormal route.
I'd mark this one as a "good episode." The only problem was that by trying to include the science fiction, while this was obviously a supernatural tale, the plot was spread a little thin. They should have concentrated on the fear brought on by the break down of logical reality and science. Luckily, the episode holds strong by interesting guest actors who were quite disturbing. (Wheelchair bound little old ladies talking to empty hallways will creep anyone out.)