In the beginning Celeste was referred to as Lillian's cousin but when Ellery confronted her in the end he said that she's Clint's couin.
Clint (to Lillian): You don't want that Vargo. That guy's still alive.
Inspector Queen: Brimmer! What are you doing here?
Brimmer: A concerned citizen coming forth with interesting information.
Inspector Queen (to Brimmer): The city stopped issuing magnifying glasses with gas lighting.
Inspector Queen: You're not leveling with us, Vargo.
Clint (to the Queens): Down where I come from we know what to do with killers--find 'em. We don't let 'em just walk around.
Brimmer: Well, Inspector, I'd say you have a brand new case on your hands.
Celeste: Obviously, you've checked my alibi, Inspector.
Inspector Queen: It's part of my job, Miss Wakefield.
Ellery: Dr. Friedland, I don't think you understand. I'm trying to solve a murder.
Inspector Queen: Paperwork! Pretty soon you'll need a judge's permission to question a suspect.
Brimmer: I think I can help you, Inspector.
Inspector Queen: You brought me an aspirin?
Inspector Queen: If you're concealing evidence, Brimmer....
Brimmer: I'm concealing nothing, Inspector. I'm merely employing methods more effective than the police.
Vargo: True genius can never be defeated. I shall create another masterpiece.
F-Troop (Forrest Tucker), Psycho (Vera Miles), Ghost and Mrs. Muir (Edward Mulhare), The Defiant Ones (Theodore Bikel) and Batman (Victor Buono and co-star David Wayne) are among the TV shows and movies with alums appearing in this episode.