Frasier: I guarantee you I would never have removed my tape from the case and replaced it with "The Best of Hall and Oates." All right, I won't be mad, just tell me, who did this? [silence] Nobody did this?
Martin: Tell you what, I did it. Now can we go eat?
Frasier: Not so fast, Dad. Okay, let's examine the evidence. A Hall and Oates tape. That rules you out, Dad. And it definitely rules out Niles.
Daphne: [sobbing] Dr. Crane...
Frasier: Or does it? Perhaps the tape is just a red herring, meant to throw me off the scent. A psychological game. There's only one of you that would combat me on that level.
Daphne: I did it.
Frasier: Aha!
Niles: You can't say "Aha!", you thought it was me.