This is the only episode based on an actual short story by Ellery Queen. The pilot for the series, Too Many Suspects. was based on an actual Ellery Queen novel.
For once, Sgt. Velie plays a crucial role in the solution to the crime instead of merely putting the cuffs on the suspect after the denouement.
Jim Backus is best known for his role as millionaire castaway Thurston Howell III on Gilligan's Island.
Emmy Reinhart reveals that she turned down the lead role in the classic film Johnny Belinda. Bad career move because Jane Wyman won an Academy Award for Best Actress in the role.
It's ironic that one of the characters dresses up as the Mad Hatter at the party. Ellery Queen co-star David Wayne played the Mad Hatter on Batman.
Ellery: 10:20. I could be home now soaking in a hot tub.
Biggers: Welcome to show biz, El.
Ellery: Look, Mr. Biggers...
Ellery: If Mr. Lockridge is so interested in turning my book into a Broadway stage play, why is he changing it?
Biggers: Well, you have to change it, it's part of the creative process.
Doyle: They couldn't start rehearsal until the boy was up in the bed. Mr. Gardner couldn't find his ears.
Biggers: He's a rabbit.
Letitia: (about the house) You see here a monument of Mr. Gardner's ability to turn mighty oaks into toothpicks.
Johnny: (about Lockridge) You think he got snatched?
Ellery: I don't know. I just got out of bed.
Biggers: (about Lockridge) If he walked away he's drowned now. It's a sea of mud out there.
Laura: Isn't that the usual thing you're told in these cases, don't call the police?
Ellery: There is the distinct possibility that it might endanger Spencer's life.
Letitia: Then by all means, let's call the police immediately, Mr. Queen.
Inspector Queen: You want me to put out a three-state alarm for a man wearing a gray top hat, a green frock coat, and... Ellery, is he armed and dangerous, too?
Johnny: (to Ellery) For a detective, you're not very smart.
Laura: What precisely are we looking for?
Ellery: Good question, Mrs. Lockridge. I wish I knew.
Gardner: One of us is playing some sort of bizarre joke, and I for one find it distinctly unfunny.
Gardner: One of us here has a very grotesque sense of humor.
Lt. Carr: It seems like we're dealing with some sort of lunatic.
Inspector Queen: Oh, I'm used to that.
Lt. Carr: Huh? Oh, no, sir, I didn't mean your son.
Ellery: Dad, come on, come on. You trust me, don't you?
Inspector Queen: No.
Velie: How'd I do, Maestro?
Ellery: Perfect. Just perfect.