After Lucy has taken the "poison aka sleeping pill" and goes to the club to confront Ricky, if you watch, when Lucy gives a big yawn from the effects of the pill, it triggers a yawn in Ethel too.
It is interesting to see in the bedroom scene where Ricky acts out a murderous scenario that they share one bed. During this period of TV history, networks usually forbade scenes where a man and woman (even though they were married) slept together in the same bed.
When Ricky and Lucy are dancing in the living room, the camera swings too far to the left, and the edge of the set wall and the adjoining bedroom set can be seen briefly
When Ricky picks up the phone you can see a stage light.
In this episode, Lucy is running away from Ricky after her attempts as a moving target don't work. Under her robe she has a frying pan and a garbage can lid to protect herself. But when she runs toward the bedroom, the frying pan accidentally falls to the floor. Looking closely, you can see Lucy loosen the pan herself. Some accident!
After Ricky puts the sleeping pill in Lucy's drink, Lucy acts like she wants to dance. When they put down their cups, Lucy's is on the right (from your view) and Ricky's is on the left. Lucy switches them, and then so does Ricky to get them back in the original position. Then notice when they drink the soda, that Lucy drinks from the one on the left and Ricky drinks from the cup on the right. They drank from each other's cup. That would mean that Ricky would be the one falling asleep, not Lucy!
(Ethel has just startled Lucy)
Ethel: Gosh, did I scare you?
Lucy: No, no. I was just getting ready to scream and throw my book out the window anyway.
Lucy: I'm not even cold yet and Ricky's lining up girls to take my place. (reading the ink blotted side of a piece of paper Ricky jotted on) Helen, Ann, Mary, Cynthia, Alice, Theodore. Theodore?!
Lucy: Now what does this grubby group of cards have to say for itself?
Ethel: Well, this is your card--the Queen of Hearts. That's you. And this card right next to it is the Ace of Spades.
Lucy: What does that mean?
Lucy: Death? (throwing the cards on the table) Well what's it doing so close to me?
Ricky: Lucy's acting crazy.
Fred: Crazy for Lucy or crazy for ordinary people?
Ricky: Crazy for anybody. She has this idea that I am going to kill her.
Fred: That doesn't mean anything. Sooner or later every married woman decides her husband wants to kill her. She's usually right.
Lucy: Well, fortunately I'm too big for the garbage disposal.
Lucy: (talking about Ricky) He won't shoot you; it's me he's after.
Ethel: Yes, but to get to you he has to go through me!
Ricky: A trained seal? Does he do an act?
Jerry: No, the seal's the manager. He has a couple of trained people.
Lucy: (to Ethel about fortune telling) Yeah, I know there's nothing to it. But I want to know what it is there's nothing to.
Lucy: Look, Ethel, we just rent this apartment from you. It says nothing in the lease about having to have our fortunes told.
Lucy: No wonder they call it The Mockingbird Murder Mystery. Every time I get that book in my hands it flies out the window.
(Lucy runs down the list of suspects in the book.)
Ricky: It was her husband.
Lucy: Her husband? He didn't have any reason to kill her.
Ricky: He was married, wasn't he?
(Lucy wants Ricky to go get her book that she threw out the window.)
Ricky: I'm a husband, not a retriever.
Lucy: (on receiving "poison" from Ricky) I got a Mickey from Ricky!
The dvd has a lost scene with Lucy suggesting some books to read to help improve Ricky's mind.
New footage was shot for the November 3, 1952 rerun while Lucille was on maternity leave. Lucy brings home paperback mystery books, which leads into a flashback of what happened the last time she read a mystery novel.
There is no "cityscape" backdrop visible outside the Ricardo's bedroom as in later episodes, but there is a small tree visible, suggesting they have a ground floor apartment. It comes to be known in "Cuban Pals" their apartment is 4A.
This was actually the fourth episode of "I Love Lucy" to air. Although it was the first episode filmed, it had to be held over for a little while, due to postproduction technical difficulties.
Filmed on September 8th, 1951