Frasier: So in they stroll. He with murderous intent. She with nary an inkling of the tragedy about to befall her. He pretends to inspect the house. "Darling, why what's this mark over here on the wall?"
Niles: "Where?"
Frasier: "There, look. Closer, closer..." And as she leans in, he does her in!
Niles: "No, Alfred, no!" [regular voice] Oh, that makes perfect sense.