In flashback, it is revealed t hat Dr. Benford conducted sensory-deprivation experiments on her test subjects, so as to sharpen their receptivity to extra-sensory perceptions. At the start of the 1980 film, a similar sensory-deprivation experiment causes the central character to undergo elaborate psychic hallucinations.
Ludo insists to Morse that they knew each other years before as university students, even though Morse can't remember him; this duplicates Tom Ripley's pretence to Dickie Greenleaf in the Anthony Minghella film.