The Big Bang Theory's Unaired Pilot, as it is generally known on the Internet, refers to the original pilot made for the 2006-2007 season that was not picked up by the network, thus it was never aired. Only Johnny Galecki and Jim Parsons were in the cast, and the female lead, Katie, was envisioned as "a street-hardened, tough-as-nails woman with a vulnerable interior". Katie was played by actress Amanda Walsh. They also had a female friend called Gilda (played by Iris Bahr). The show's original theme music was also different, using Thomas Dolby's hit "She Blinded Me with Science".
Leonard and Sheldon encounter a young woman named Katie crying on the curb, having been left homeless by a break-up with her boyfriend. Leonard, despite Sheldon's objections, invites her to dinner and then to stay a few days at their apartment. She is abrasive, sexy, hard, and sarcastic, but she softens a little when she discovers that the guys aren't trying to get something from her. In the end, she decides she'll crash at their place for a while.
The episode opens with Leonard sitting in the sperm bank waiting for Sheldon to finish his deposits, which he eventually finished using a magazine of women with big butts (his fetish). At the desk, after annoyingly finishing the receptionist's crossword puzzle, they are told that they won't be paid in cash but with checks.
On their way from the sperm bank, the duo happen across a crying girl called Katie, who is sitting on the street after a bad break up with her boyfriend has left her homeless. Leonard invites her to the restaurant, to Sheldon's dismay. When Sheldon can't figure out a good excuse, Leonard invites her to move into their apartment.
Whilst Katie is showering, a nerdy friend of Sheldon and Leonard called Gilda shows up at the apartment. Gilda, who is shown to have a thing for Leonard and fantasizes about marrying him and having kids, feels threatened by Katie's presence but relaxes after Katie says she's not interested.
Katie goes out drinking and arrives back at their apartment late at night, waking Leonard by smashing a lamp. Katie starts ranting to Leonard about her life and why it sucks, using the whiteboard, drawing colorful diagrams to explain her point. Leonard points out that her problems weren't caused by her mother, boyfriend etc., but by her making stupid decisions. Katie misguidedly assumes that Leonard is calling her "stupid" (even though he is not) and as a result, she gets offended and moves out.
Leonard goes to Katie's place of work, the cosmetics counter in a department store, and even though he had nothing to apologize for, apologizes to her anyway. Katie comes back at the end of the episode explaining that staying there is her only rent-free choice. She takes Leonard, Sheldon and Gilda out dancing and they show their awkward dance moves.
All the cast were not credited in the Unaired Pilot.
- Johnny Galecki as Leonard Hofstadter
- Jim Parsons as Sheldon Cooper
- Amanda Walsh as Katie
- Iris Bahr as Gilda
- Vernee Watson as Althea (sperm bank receptionist)
- Mitzi McCall as Cosmetics counter customer
- Leonard: How is it that you can recite pi to 80 decimal places, but you can't recognize sarcasm?
- Sheldon: Well, I don't think the two are related.
- Sheldon: (explains why he's uncomfortable) This isn't where we normally sit. We sit at that table over there. That's our table.
- Katie: What's the difference?
- Sheldon: What's the difference!?
- Leonard: Here we go.
- Sheldon: (clears his throat) That table is closer to the kitchen, resulting in the food arriving hotter, and yet not so close as to be distracting. In the summer, the nearby air vent provides adequate cooling. In the winter, it's protected from the outside air. It's generally in the server's eye-line, making signaling efficient. I could go on, but I think I've made my point.
- Katie: (sees Leonard holding a green light saber replica) Okay, if that thing vibrates, I'm gonna need to borrow it.
- Katie: Ipso facto, I drink till I'm flatso!
- Leonard: (looking at Katie's drawing on his board) I'm a spaceship on wheels?
- (Next morning)
- Sheldon: (looking at the drawing on Leonard's board) Ghost on roller skates?
- Leonard: I'm starting to think it's a penis.
- Leonard: I think she (Katie) left because of something I said.
- Sheldon: Great, jot it down in case she comes back.
- Leonard: Look, I'm not very good at talking to people.
- Katie: And?
- Leonard: And? No, that's it, that's all I got.
- Katie: (to a girl smiling at the dancing nerds) They don't get out much.
While originating portions of the Broadcast Pilot's plot, jokes, settings and characters, the Unaired Pilot has several key differences from the eventual official pilot, they include:
- The opening segment is much different from the Broadcast Pilot. It features a different song and a different opening.
- The characters Penny, Howard and Rajesh have not been created yet. Penny's precursor is Katie who has a different personality from Penny.
- The opening scene at the sperm bank plays out largely as it did in the Pilot, with two significant differences:
- Leonard and Sheldon have a geeky friend, colleague and love interest Gilda. As a female nerd with an interest in Leonard, she does appear to be a primitive Leslie Winkle-type character, although a bit different.
- Leonard and Sheldon dress in a different fashion which is more old-fashioned, rather than youthful, and Leonard wears dark suits (which eventually became the usual costume choice for Priya).
- Sheldon is not asexual as he had slept with Gilda and has a fetish for women with large hind quarters (butts). Actually, he contends that large buttocks enhance a woman's ability to bear children. He has also seen seven women naked, some of whom aren't even his relatives.
- Sheldon doesn't have a spot in his home, but rather a table at The Bombay Palace.
- Sheldon is significantly different from his series counterpart: he is sexually active, he frequently masturbates (as opposed to his later counterpart asexual Sheldon) and has multiple fetishes, likes dancing and is a bit more social than his counterpart. However, some parts of him were carried to the original Pilot.
- Sheldon likes to dance as opposed to his later counterpart. (This change stood out especially in season 3's "The Gothowitz Deviation" and result in him not dancing until season 4's "The Agreement Dissection".)
- The set of the apartment is different and there is no broken elevator or indication that the apartment building has an elevator. The lighting in the apartment is also a lot dimmer.
- Katie's mocking and mean streak carried over to the regular series when Penny gets real mad.
- Sheldon's voice is deeper in this episode than it is in the actual series.
- Katie was cut from the series due to an audience survey. She was criticized for being too mean towards Leonard and Sheldon.
- Positive reviews came in about the two guys, Leonard and Sheldon, so Chuck Lorre decided to add two more guys (Howard and Rajesh) into the mix.
- Since the pilot spurred a negative reaction, the show was almost cancelled from the start.
- Katie works at the cosmetics counter in a department store. However, when the character is changed into Penny, she is a waitress at The Cheesecake Factory.
- Surprisingly, the only character other than Sheldon and Leonard to appear in the broadcast Pilot is Althea, the nurse at the sperm bank. Her character has made several more guest appearances on the show since. Her hair is different here from her hair in the aired pilot.
- Sheldon's stated reason for his preferred table at the restaurant would later be adapted for the reasons for his spot.
- This episode makes numerous references to a sexually active Sheldon, as opposed to the largely asexual Sheldon of broadcast series, most notably that Gilda and Sheldon admit to previously having sex at a Star Trek convention (Howard doing something similar was revealed in season 5's "The Stag Convergence" and Howard encouraging him to meet Amy by reminding him of Spock engaging in 'pon farr' which was how Sheldon acted like to arouse Gilda). Sheldon also apparently has a fetish for women with large butts, and brings a magazine of such women to the sperm bank for arousal.
- The main series Sheldon does not engage in intercourse until Season 9's "The Opening Night Excitation".
- Leonard wielding his lightsaber upon hearing a noise late at night, and Sheldon's difficulty of spotting sarcasm (minus Leonard's acknowledgement of this flaw, regarding Sheldon's high intellect) would later be used in "The Big Bran Hypothesis".
- Sheldon describes the same calculations on his whiteboard in both pilots, but the actual physics are different.
- In a scene, Katie touched Sheldon's food and he seemed fine with it, which contrasts from the series where he is extremely uncomfortable with it.