CPR (Clean, Pretty, Reliable): Subverted over and over again in the climax. Mulder performs CPR on Amy, but it doesn't work. He does the typical keep-trying-even-when-it's-hopeless thing, but it still doesn't work. But then suddenly it does work... BUT only because Lucy mystically took on Amy's death, sacrificing herself to save the girl and end her own torment.
Psychic Nosebleed: Lucy gets a very big nosebleed very quickly at the beginning of her first psychic episode. A bit of an inversion in that the Psychic Link only gave Lucy a nosebleed because Amy had a regular, non-psychic nosebleed at the time. But some of the blood that came out of Lucy's nose was Amy's blood.
Single Issue Psychology: Scully suggests Mulder that he takes the case personally because of Samantha. Mulder defends himself that it's way too simplifying.