The Staircase Implementation

​"The Staircase Implementation" is the twenty-second episode of the third season of ''The Big Bang Theory. ''This episode first aired on May 17, 2010

Summary
Leonard spins the tale to Penny of how he met Sheldon and what happened to break the elevator.

Extended Plot
Penny is about to do her nails, when she hears Leonard and Sheldon fighting over the setting. Leonard comes over to Penny's apartment and asks if he can sleep on her couch for the night. When Penny remarks that Leonard is nuts for living with Sheldon, he tells Penny the story of how he first met him seven years ago.

Leonard starts out with explaining how he had just started at Caltech and he needed a room for rent. The elevator was still working in the apartment building and he sees Sheldon's previous roommate, "Sebastian" (Stephen Yuen), leaving and warning him about Sheldon being crazy. He does not heed this warning, thinking the previous roommate was the crazy one. After Leonard mistakenly knocks on his future transvestite neighbor's apartment door by mistake, he meets Sheldon. Sheldon first quizzes Leonard about his job and his science fiction character preferences before he allows him to enter. At this point, Sheldon's apartment is far more empty, having only two s instead of the couch and armchair, although the lawn chair is in the same position as his present-day "spot". Sheldon gives a series of interview questions to verify whether or not Leonard is a good and worthy roommate to have and gives him a tour, which includes showing him his future room with "DIE SHELDON DIE" painted on a wall by the previous roommate. After working out seemingly countless pages of the roommate agreement, Leonard moves in.

Penny cannot understand how Leonard decided to stay with Sheldon, and has no sympathy for him, following which Leonard tells her about when Sheldon kicked Joyce Kim, Leonard's girlfriend, out of the apartment. This shocks Penny, and she asks why he still stayed after that. Leonard tells her it turned out to be a good thing as Kim was a spy and Leonard had been working on classified  for the government: Joyce Kim was trying to seduce Leonard for information, which, due to Sheldon, proved unsuccessful as she then defected back to North Korea. Penny now knows half of the story now: Leonard stayed with Sheldon because the latter protected him from going to prison for.

Leonard mentions that the other part of his story has to do with the elevator's destruction, and he continues the story. Sheldon comes home from work and he meets Raj and Howard who work at the university too, for the first time. He finds that Leonard has replaced Sheldon's lawn chairs with the that is currently in the apartment, which Sheldon isn't too happy with initially. Soon, after a lot of switching spots, Sheldon finally claims his "spot" on the couch. After the other guys leave due to Sheldon's annoyances, they go to Howard's place.

Leonard discovers that Howard has a, which he claims could break the if it was running on the fuel Leonard was working on. Leonard tells Penny that he had some rocket fuel in the apartment and they went back to mix some. However, Sheldon notices that Leonard did not adjust the fuel for Howard's rocket size correctly, and the fuel starts smoking, causing Leonard to. Leonard attempts to take it outside and confine the smoking fuel to the elevator, but Sheldon knows precisely how long he has until it explodes, so he pushes Leonard out of the elevator before stepping out himself and closing the door. Within seconds, the fuel explodes, explaining why the elevator no  longer works. Leonard explains his continued friendship with Sheldon by pointing out that Sheldon saved his life and didn't rat him out to the landlord, the police, or.

While Penny gets a little annoyed at the fact that he is the reason that she has to use the stairs every day, Leonard asks her what she did seven years ago. While she lies to him about doing and studying hard, it is revealed to the audience that she was relieved holding a negative.

Leonard goes back to the apartment and apologizes to Sheldon for his argument over the thermostat. However, when Leonard turns the TV on and tries to watch, a whole new fight starts again, with Penny laughing at it as she is packing up her set.

Critics
"A terrific episode. It wasn't as emotionally resonant or as funny as it might have been but I have no complaints with a real good faith effort to apply actual characterisation to these characters...First off I was delighted to see a flashback story; just to see The Big Bang Theory try something new was good. But the flashback is always a rich source for sit coms and this was no exception...This isn't the show's best episode by any means. But it's one that does such a good job with continuity, characterisation and just changing the formula that it encourages me as a viewer to invest more in future episode. Great work." - The TV Critic's Review

Quotes

 * (Penny is about to do her nails)
 * Penny: OK Babydoll Pink, let's see if you can cover up the fact that I got my dad's feet.
 * (Leonard and Sheldon have started fighting which can be heard from Penny's place)
 * Leonard: 2 degrees Sheldon! I just wanna turn up the thermostat by 2 degrees!
 * Sheldon: Let me point out that 2 degrees can be the difference between water and steam!
 * Leonard: Yes, if we lived in a tea kettle!
 * Sheldon: This is the temperature you agreed to in the roommate agreement!
 * Leonard: Aw, screw the roommate agreement!
 * Sheldon: No, you don't screw the roommate agreement, the roommate agreement screws you!
 * Leonard: You know what?! Go to hell and set their thermostat!
 * Sheldon: I don't have to go to hell! At 73 degrees, I'm there already!
 * (Leonard slams their door and knocks on Penny's.)
 * Penny: Who is it?
 * Leonard: Leonard.
 * Penny: Hang on.
 * (She walks on her heels to get to the door so she doesn't ruin her nail job.)
 * Leonard: Can I sleep on your couch tonight?
 * Penny: Uh, well you can try, but the people across the hall are being very noisy.
 * Leonard: You heard that, huh?
 * Penny: Apparently, the one fella tried to adjust the thermostat, then the other fella went bat-crap crazy.
 * Leonard: So you agree, he's nuts!
 * Penny: Well, not as nuts as the guy who chooses to live with him.
 * Leonard: Believe it or not, he was worse when I met him.
 * Penny: (Naively chuckles) Oh, I do not believe that.
 * Leonard: You are so naive. Just like I was seven years ago.
 * (Leonard starts telling the story of how he met Sheldon.)
 * Leonard: "I just started at the university."
 * (It is the year 2003 and we see that when Leonard was younger, he originally had a "classic" Weird Al hairstyle, tortoiseshell glasses and Raj's current attire. He then sees Sheldon's previous roommate leaving the elevator, which was still operational at the time.)
 * Leonard: Hi, excuse me, I'm looking for Sheldon Cooper's apartment?
 * Ex-Roommate: Oh, I bet you're here to check out the room for rent?
 * Leonard: Yeah.
 * Ex-Roommate: Run away dude!
 * Leonard: What?
 * Ex-Roommate: Run fast, run far!
 * (Back in 2010)
 * Leonard: That should have been my first clue.


 * 
 * Leonard: (voiceover) Anyway, I went upstairs and knocked on the door.
 * (2003 Leonard walks over to 4B's apartment and knocks. The door is opened and he is confronted by a large muscular African-American man with breasts and dressed as a woman)
 * Louie/Louise: Yeah?
 * (Long pause, as Leonard is speechless. Louie gives him an impatient look)
 * Leonard: ... Dr. Cooper!?
 * Louie/Louise: Nah, you want the crazy guy across the hall.
 * Leonard: (voiceover) In retrospect, that was clue number 2.


 * 
 * Sheldon: What is the sixth noble gas?
 * Leonard: What?
 * Sheldon: You said you're a scientist. What is the sixth noble gas?
 * Leonard: Uh, radon?
 * Sheldon: Are you asking me or telling me?
 * Leonard: Telling you?
 * (Sheldon gives Leonard an impatiently angry look)
 * Leonard: Telling you.
 * Sheldon: All right. Next question. Kirk or Picard?
 * Leonard: Oh, uh-- Well, that's tricky. Um-- Original Series over Next Generation, but Picard over Kirk.
 * Sheldon: Correct. You've passed the first barrier to roommatehood. You may enter.


 * 
 * (Leonard is about to sit in a lawn chair)
 * Sheldon: No, that's where I sit!
 * Leonard: What's the difference?
 * Sheldon: This seat is ideally located, both in relation to the heat source in the winter and a cross breeze in the summer. It also faces the television at a direct angle, allowing me to immerse myself in entertainment or gameplay, without being subjected to conversation. As a result, I've placed it in a state of eternal dibs.


 * 
 * (Sheldon is busy getting Leonard to sign the roommate agreement )
 * Sheldon: Roommates agree that Friday nights shall be reserved for watching Joss Whedon's brilliant new series, "Firefly".
 * Leonard: Does that really need to be in the agreement?
 * Sheldon: Well we might as well settle it now, it's gonna be on for years.


 * 
 * Sheldon: Mmm, I assure you, you'll be sorry you wasted your money on an iPod, when Microsoft comes out with theirs.
 * Raj: OK, do you have an opinion about everything?
 * Sheldon: Yes.
 * Howard: You just assume you're always right?
 * Sheldon: It's not an assumption.


 * 
 * Leonard: Oh, it's time for Babylon 5.
 * Sheldon: But we don't watch Babylon 5 in this apartment.
 * Leonard: Why not?
 * Sheldon: Because no one likes Babylon 5.
 * Leonard: Well, I like it.
 * Raj: Me too.
 * Howard: So do I.
 * Leonard: There you go, 3 against 1.
 * Sheldon: They don't get a vote. It's 1 against 1 and according to the roommate agreement, all ties will be settled by me.
 * Leonard: But I said no to that.
 * Sheldon: And I said yes. And I settle all ties.


 * 
 * (In 2003: Leonard, Raj and Howard are at Howard's place after leaving Sheldo . Howard's mother, who had an even younger, louder and very masculine voice at the time, is yelling at Howard .)
 * Mrs. Wolowitz (shouting from another room): HOWARD, ARE YOU HAVING A PLAYDATE?!
 * Howard: (also shouting back): DON'T HAVE PLAYDATES, WE HAVE COLLEAGUES!
 * Mrs. Wolowitz: DO THEIR PARENTS KNOW THEY'RE HERE?!
 * Howard: NO, BUT IF YOU KEEP SCREAMING, MAYBE THEY'LL HEAR YOU!
 * Leonard: Is that your dad?
 * Howard: If she grows anymore hair on her face, yes.


 * Mrs. Wolowitz: HOWARD, WHAT HAPPENED TO THE OREOS I LEFT ON THE COUNTER?!
 * Howard: I HAVEN'T SEEN YOUR OREOS, (Doesn't notice that Raj is eating them) JUST TAKE YOUR BATH WITHOUT THEM!


 * 
 * (Leonard has just told Penny that Howard had a model rocket and only needed some of the fuel that Leonard was making for the government to get it going)
 * Penny: So why was it his lucky day?
 * Leonard: Well it turns out I had a little rocket fuel in the apartment.
 * Penny: What were you doing with rocket fuel in your apartment?
 * Leonard: Well, Joyce Kim was kind of curious about what I did for a living, and I was gonna, kinda...show it to her. It's not important, the point is the guys and I went back to the apartment.
 * Penny: OK, but are we ever going to get to the elevator?
 * Leonard: Yeah, we're really close, we're at the apartment....
 * (In 2003: Leonard is incorrectly mixing rocket fuel for Howard's model rocket.)
 * Leonard: The trick is to mix it in a Tovex in order to create a combustible gel that will generate over 8000 kilonewtons of thrust.
 * (Howard and Raj excitedly chuckle)
 * Raj: Coooool!
 * Sheldon: Won't work.
 * Leonard: Excuse me, but I've been working on this a long time. Trust me, it will work.
 * Sheldon: You don't see your mistake, do you?
 * Leonard: There's no mistake.
 * Sheldon: This is for a full scale rocket, not a model.
 * Leonard: Well I've adjusted the formula.
 * Sheldon: Not correctly.
 * Leonard: OK, I've had it with you! You might be an expert on theoretical physics, and science-fiction programs, and where to sit on a freaking couch! But this is "applied" physics, and when it comes to applied physics.... (rocket fuel starts sizzling) ..... Ahh, uh-oh.
 * Howard: What's happening?
 * Leonard: A bad thing, a veerry bad thing. Get the door! Get the door! Get the door! Get the door! Get the door!
 * (Sheldon turns their apartment's flag upside down, while the other 3 go out into the hallway where Leonard waits for the elevator.)
 * Howard: You're waiting for the elevator?!
 * Leonard: Oh, right!
 * (Leonard starts to go down the stairs, when the elevator arrives.)
 * Raj: Wait, it's here!
 * Leonard: Ahhhhhhh! (Goes back up and into elevator. As the door closes, Sheldon barges past Raj at an unusually quick pace, pushes the elevator doors back open and takes the rocket fuel out of his hands.)
 * Sheldon: Give me that! (Pushes Leonard out, presses the down button and exits the elevator. The doors close)
 * Leonard: What did you do that for?! I had plenty of time-!
 * (There is a sudden, very loud explosion in the elevator, destroying it. All of them, except Sheldon are in shock and horror.)
 * Sheldon: You're welcome. (Sheldon goes back inside, with Leonard still dazed.)
 * (In 2010)
 * Leonard: Not only did Sheldon save my life, he didn't rat me out to the landlord. Or the police, or Homeland Security.
 * Penny: OK, so basically, you're the reason I have to walk up and down 3 flights of stairs everyday?
 * Leonard: So, I did something stupid, I'm sure you did stupid things when you were younger; what were you doing 7 years ago?
 * Penny: Excuse me, I was in high school, studying, keeping my nose clean, doing volunteer work for the community...
 * (In 2003, a teenage Penny back in Nebraska with a boyfriend, is doing a pregnancy test.)
 * Penny: Not pregnant. Yes! (High-fives boyfriend.) Ha ha!

Trivia

 * In this episode, the hitherto unseen characters of Joyce Kim, a North Korean spy who dated Leonard, and the pair's original neighbour, Louie/Louise, the "two hundred pound with a skin condition" are seen.
 * Sheldon's lawn chair faced the television at a direct angle, thus discouraging conversation. But as explained in the pilot and "The Gorilla Experiment", his spot faces the television at an indirect angle, thus encouraging conversation. (Apparently over the years he learned to tolerate company.)
 * During the second of three sets of questions, Sheldon asks if Leonard has a vehicle. Leonard has a car, but asks, "Can't you drive?" And Sheldon confesses that "I can. I choose not to." During his simulated driving lessons he actually proved to be a very bad driver in "The Euclid Alternative". However, his face slightly es as he says it, which is one of Sheldon's facial tics that indicates he is lying.
 * Sheldon makes two blatantly wrong predictions in flashbacks: would run "for years" and told Raj that he would be sorry he wasted his money on an {{W}Apple iPod}} when  "comes out with theirs" (implying the the  would be more popular than the iPod series). In reality, Firefly only lasted for one season before being cancelled by  (leading to Sheldon's hatred of Fox and, by extension, ) while the Microsoft Zune dwindled in sales from the moment it was released (with the entire line being discontinued a mere five years later after initial release), while the iPod became a global icon when it comes to music players.
 * In Howard's room of 2003 they showed a and a slimline, neither of which was available then (he most likely got elected for testing them since he has a master's degree in engineering).
 * While forming the roommate agreement Sheldon finishes the section for television & movies and moves onto section 9: miscellanea, making television and movies section 8. However, in the flashback with Joyce Kim in Leonard's bedroom, Sheldon states that section 8 is visitors (most likely, section 8 was for both).
 * When Leonard, Howard, and Raj are playing on Sheldon's, you can closely hear the Waluigi Stadium/Wario Coliseum music from Mario Kart: Double Dash.
 * The present Leonard in 2010 refers to events seven years ago (2003) and states, "I’d just started at the university." The past Leonard introduces Howard and Raj to Sheldon with, "They work at the university, too." These allusions to such an early point in time at the university, perhaps unintentionally, imply some of the main characters are not faculty members in the flashback. Since Leonard was born in 1980 ("The Alien Parasite Hypothesis"), and got his doctorate at twenty-four ("The Cooper-Hofstadter Polarization"), he was not finished with graduate school when he started at Caltech. Similarly, Rajesh was born in 1981 ("The Grasshopper Experiment"), which means at twenty-one or twenty-two years old, he probably wasn't finished with graduate school either. Howard, also born in 1981 ("The Bad Fish Paradigm"), only has a master's degree, thus, the chronological events presented may not be a continuity concern regarding his character. Note this possible mistake has no bearing on child Sheldon, though. Further, Leonard must have completed his doctoral studies at Caltech, working as a graduate research assistant, and the same can likely be said of Raj.
 * Although the episode "The Nerdvana Annihilation", Season 1, in 2008, Leonard claims that the elevator has been broken for two years (2006). This episode reveals that the elevator has been broken since 2003.
 * Given the year of 2003, the episodes of Firefly that Sheldon is referring to places the episode's date(s) in 2003 between June 28 and December 13.
 * In "The Jerusalem Duality": Penny: "I don’t understand, exactly how did he get any friends in the first place?" Howard: "We liked Leonard." The episode of this article clearly establishes that.
 * Sheldon gets upset when someone phrases a response with an air of uncertainty, as when he asks Leonard about the sixth noble gas. This is also evident in "The Dead Hooker Juxtaposition", when Alicia pondered "freakishly feline."
 * Sheldon says to Leonard, as he introduces his room, "Huzzah!" He previously said this while discussing fifteenth century historical inaccuracies at the in "The Codpiece Topology".
 * Sheldon put Leonard in his spam folder after he forwarded him a picture of a cat playing the piano, entitled "This is Funny." In "The Panty Piñata Polarization", Sheldon told Penny she violated his rule about forwarding email humor, the photo of the cat who wants to “has cheezburger," and gave her a "strike." Sheldon considers Internet banality.
 * One of Leonard's whiteboards contains an analysis of propulsion systems, specifically, the chemical equation for the spontaneous  decomposition of hydrazine, followed by an equation for the endothermic dissociation of ammonia into hydrogen and nitrogen. Referenced thrust values, including those for the  (SSME) and, are also provided. Sheldon's work on his ((W|whiteboard}}s are on.
 * It is revealed that Sheldon owned a Palm Treo.