Larry mentions a recurring dream about his Aunt Louise consuming his flesh; in "Harvest," he said that until the age of thirteen he had recurring nightmares about that same aunt harvesting his internal organs with "these fingernails."
Charlie has a dream in which his father Alan ([Judd Hirsch) is shot during a store robbery. He then has a dream about his late mother, Margaret Eppes (played by JoBeth Williams in a guest appearance), who appears in one of Charlie's dreams in present-time. It is the first dream he has had of her since her death. She tells Charlie she can't stay long and that he has a question to ask her. Charlie cannot think of what that question might be but she tells him it will come to him. Later, Alan has an imaginary conversation with his late wife. (Williams and Hirsch had starred in the film Teachers (1984).) Meanwhile, the team investigates a serial killer of young women. Academy Award-winning actress Olympia Dukakis appears as a suspect's wealthy mother.
Charlie mentions the Dyson uses centrifugal force. ANY credible mathematician would know that is a myth and doesn't exist.