Recap / The X-Files S02 E11 "Excelsis Dei"

When an orderly at the Excelcis Dei Nursing Home claims to have been raped by an elderly (and, what's more, invisible) in-patient, Scully insists on an investigation. Once there, they find that the patients seem unusually spry and lucid - until the accused rapist unexpectedly drops dead from a rare poison that he could not conceivably have access to. Could a revolutionary new treatment for Alzheimer's be responsible? Or are the spirits of the dead exacting horrible revenge for the abuses they suffered? And what is the role of Gung, the one orderly everyone seems to like?