The Roommate Transmogrification Season 4, Episode 24 -  Aired May 19, 2011

The Roommate Transmogrification

Bernadette receives her Ph.D., leaving Howard as the only scientist in their group who isn't a doctor. Meanwhile, Raj becomes Sheldon's new roommate after Leonard starts staying with Priya in his apartment and Raj overhears their "Star Trek"-inspired bedroom fantasy.

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Guest Stars: Carol Ann Susi as Mrs. Wolowitz, Aarti Mann as Priya, Brian George as Dr. Koothrappali, Alice Amter as Mrs. Koothrappli

Writers: Chuck Lorre (Story), Steven Molaro (Story), Eddie Gorodetsky (Story), Bill Prady (Teleplay), Eric Kaplan (Teleplay), Jim Reynolds (Teleplay)

Director: Mark Cendrowski

Available on iTunes

Episode Notes

  • The title refers to the change of Sheldon's roommate from Leonard to Raj.

> The Flag of Apartment 4A

When Raj starts staying in Leonard's room because Leonard and Priya are staying in his apartment, Sheldon gives Raj a lapel pin version of the apartment flag, which "Leonard was too cool to wear."

Episode Quotes

Penny: What do you mean new roommate? What happened to Leonard?
Sheldon: The same thing that happened to Homo Erectus. He was replaced by a superior species.
Raj: I'm the new homo in town.

Penny: So that means, you're a doctor, you're a doctor, you're a doctor, you're a doctor and, Howard, you know a lot of doctors.

Sheldon: Here's an interesting fact about alcohol: Man is not the only species that ferments fruit in order to become intoxicated. Can you guess what the other is? Hint: sometimes they pack the alcohol in their trunks.
Penny: Monkeys.
Sheldon: When does a monkey have a trunk?
Penny: When a suitcase just won't do.

Penny: Hey, Sheldon, did you change your Wi-Fi password again?
Sheldon: Yes, it's "Penny get your own Wi-Fi"; no spaces.

Raj: Can I bring girls here?
Leonard: You? Sure. Bring as many as you want.
Raj: Okay, deal.
Leonard: Just not against their will.

News Stories

Title Date Posted
Episode 4.24 Ratings May 20, 2011

The fourth season finale of The Big Bang Theory posted an increase on last week's ratings.  Full story

CBS Announces Season 4 Finale April 30, 2011

CBS has announced the fourth season finale of The Big Bang Theory.  Full story

Episode Tournaments

WinnerThis episode won our Season 4 episode tournament in June 2011.


The guys and Priya are eating at The Cheesecake Factory when Bernadette announces she's getting her PH.D., causing the others to mock Howard about his lack of a doctorate. Later, Raj overhears Leonard and Priya engaging in a Star-Trek role-playing game in the bedroom, causing him to become uncomfortable in his own apartment. Raj tries to sleep at Howard's, but the side-effects of Mrs. Wolowitz's new hormone replacement therapy make him ill at ease there.

As Sheldon video chats with Amy, he hears a knock at the door. Raj wants to crash on Leonard's bed since Leonard is over at his apartment with Priya. Sheldon is uncomfortable with the idea at first, but after Raj signs a indemnification form he's fine with it. The next morning, Leonard arrives home to his apartment and accidentally sits on Raj in the bed. Leonard wonders why Raj is sleeping here. Raj explains he couldn't sleep in his own apartment because of what Leonard and Priya are doing, and since Leonard was sleeping in his bed it seemed fair. Raj wonders why they can't stay in Leonard's bed, but Leonard reveals Priya doesn't get along with Sheldon. Leonard suggests that until Priya gets her own place, Raj can stay in his bed and he'll stay in Raj's apartment.

In the university cafeteria, the guys are still mocking Howard about Bernadette's success. Sheldon arrives to congratulate Raj on his blood work passing the test, and to get him to sign a temporary roommate agreement. That night in the apartment, Raj has prepared dinner for Sheldon in a much fancier way than Leonard ever did. Penny comes over to check whether Sheldon changed the Wifi password and wonders why Raj is staying here. Elsewhere, Bernadette gives Howard an expensive watch.

Back in Sheldon's apartment, Raj and Penny have been drinking wine and are too inebriated for Sheldon, who decides to call it a night. Raj and Penny bond over their mutual concerns of Leonard dating Priya. Back in Raj's apartment, Leonard and Priya are kissing when her parents start a video chat. Priya gets Leonard to hide in the bedroom while she talks to her parents. When Priya's mother mentions she's coming back to India next month, Leonard comes out of the bedroom to express his surprise. Leonard reveals their relationship to the Koothrappalis, while Priya storms out.

The next morning, Penny wakes up to find herself in bed with Raj. Penny is in shock and tries to talk to Raj who, even after what they've just done, still can't talk to her. In the apartment living room, Sheldon finds Leonard sleeping on the couch. Howard knocks on the door to say he'd had a fight with Bernadette. As Sheldon, Leonard and Howard are in the living room, a dishevelled Penny enters with a half-naked Raj.