Amy and Leonard drive to Arizona together to pick up Sheldon because he had been robbed while on his train trip. Penny has a job interview at Bernadette's company as a pharmaceutical rep. Howard has to deal with Stuart having not moved out of his mother's house.
Sheldon is at a train station wearing no pants, no shoes and one sock looking quite disheveled after being robbed. He tries to tell random people that he is a physicist and that he is not crazy though everybody he meets acts like he is. [He is not since his mother had him tested.] One woman is knitting and he asks if she is making a pair of pants. He asks to use a man's cell phone and starts to describe his pajama rules. Another man runs away as he describes the difference between subatomic particles. He is left alone yelling that this legs are cold.
Penny with her new short haircut is doing yoga in apartment 4A as Leonard says good morning to her. He declines to do yoga with her. Leonard gets a call from Sheldon who is at the Kingman, Arizona police station and asks Leonard to come and get him. Everything he owned was stolen from him and he is wearing borrowed pants. Penny can't come with him because she has a job interview and doesn't want to hear Sheldon complaining about her short hair for six hours. He asks Penny why he shouldn't take Amy and gets upset when she can't think of one good reason.
Howard is taking Raj to work since his car is being worked on. He is having his windows untinted so the world can see his hot girlfriend. Howard is explaining that Stuart is supposed to be moving out of his mother's house and complaining how chummy they had become. It's creepy. Not like Howard and Raj; more like Raj and his dog. They call each other Debbie and Stewie and they get all giggling around each other. Raj wonders if Howard is worried that he is being replaced as her son or that she may becoming her lover which really bothers Howard.At the police station, Sheldon inquires about his stolen possessions and lectures Officer Hernandez on Sherlock Holmes and his investigation techniques. If one eliminates everything else, whatever is left is true no matter how implausible. The officer hasn't done that. Sheldon reminds him that there are lots of Sherlock Holmes books and no Officer Hernandez books.
Amy and Leonard are enroute to get Sheldon. She is glad to have come, but is peeved that Leonard was called instead of her.
Penny is with Bernadette just prior to her interview and is nervous since she hasn't had a job interview in years. Bernie describes Penny's good points and can only come up that she is cute and funny. She doesn't have any experience in sales except for a bikini car wash. Bernadette had her take that off her resume. It seems that selling pharmaceuticals is like being a waitress pushing the bad stuff onto the customers. Bernadette talked her up to Dan and wouldn't have done it if she didn't think she could do the job. Penny wants to cancel. Bernadette tells her that she wants to do something she's good at like getting her a job at the "sitting-around-in-your-yoga-pants-doing-nothing-factory.”
Howard and Raj enter his mother's house and asks if she is descent. Since Raj is now seeing a naked woman, he doesn't want to confuse him as to where her boobs should be. Stuart comes in confusing Howard since he thought Stuart had moved out. Stuart was going to, but since he still has no place to go, he and Debbie decided that he should stay especially since they get along so well. His mother calls for "Stewie" to help her find her eyeglasses. Stuart replies that he'll be there in a minute "Deb-Debs". Stuart thinks they are on her head while Howard suggests that they might be in her neck. Howard wonders why his mother hadn't spoken to him about this arrangement. As Stuart is leaving he tells Howard that maybe he should call home more often. Note that Raj is obviously still seeing Emily.Sheldon is staring at Officer Hernandez and then again asked about his stolen property. He claims that they are doing everything they can while he is munching on Doritos. Sherlock Holmes used cocaine to sharpen his senses; however, Sheldon claims that the officer's Doritos are probably going to do the same thing. Amy and Leonard show up. Sheldon excitedly hugs Leonard and wants to know why Amy came. Amy reacts that he is her boyfriend and that she just drove six hours to help him out. Isn't there is anything he wants to tell her she inquires. Sheldon says that he can't say it in front of the police officers which causes her to smile. Amy asks him to whisper to her. He tells her "shotgun" meaning he wants to ride in the front seat going back since he doesn't want to yell shotgun in a police station. Sheldon run out while Amy again looks frustrated and leaves with Leonard.
On their way back, Leonard asks Sheldon to tell them about his trip. He went to New York, Chicago, Atlanta, Denver, Seattle etc. When asked how he liked those cities, he explains that he never left any of the train stations. The stations are where all the cool trains were. He never left the stations or had a single piece of fruit.
Penny is at her interview with Dan as a pharmaceutical rep and keeps explaining that she likes people over and over. When asked how her previous job experience prepared her for sales, she tells the interviewer that she convinced many large customers to order extra cheesecake; one person that even had an insulin pump. The interviewer uses an insulin pump. Penny again tells him that she likes people.
Howard says he's unhappy about a man in his thirties, though Raj thought he was 45 (he's actually 39), living with his mother. Raj says that since she is lonely and he needs a place to stay what is wrong with that, besides who cares. Howard asks if Raj would mind if he slept with Raj's mother. Since Howard is his best friend and she is in a bad marriage, Raj would give Howard his blessing. Howard decides to call her to raise his objections. He doesn't get her; however, the answering machine has a message from both his mother and Stuart on it.During the interview, Penny is asked how she would suggest to someone to switch from a competitor's product to their company's drug. She stares for a moment and then tells him that she could offer the client a bikini car wash. Penny shakes her head and tells him that she is wasting the interviewer's time. Also she doesn't want Bernadette to know how badly she failed at the interview because she’s scared of her. The interviewer thought he was the only one scared of her. Everyone thinks that she is so nice with that squeaky little voice. He didn't want to meet with Penny, but was afraid to say no to her. Penny also couldn't say no to Bernadette when she got her the interview and feels that she is something of a bully. When the interviewer had to tell Bernadette that her project was being cut, he couldn't do it to her. They start to laugh together and agree not to tell her about the interview; therefore, Penny got the job.
Driving back, Sheldon is explaining about the brands of ketchup he found at various hot dog stands. While Sheldon wants to discuss the mustard issue, Amy tells him that she has been in the backseat stewing for two whole hours. How could he have left her without even saying goodbye and then call Leonard instead of her. Sheldon wants to have a private moment with Leonard and asks Amy to cover her ears. He then claims to want to have coitus with her just to see if she can hear him. Sheldon didn't want to call Amy because he didn't want her to know that he couldn't make it on his own. (And Amy's alternative to that was to have them move in together.) Leonard thinks that it is no big deal. Sheldon says that he feels that way since Leonard supposedly idolizes Sheldon and nothing could knock him of the pedestal Leonard has put him on. Leonard sarcastically tells Sheldon that he is a god to Leonard. Leonard just tells Sheldon that he should tell Amy. He does and Amy replies that she knows he is not perfect and that she is fine with that. He asks for another private moment as Amy covers her ears smiling. Sheldon then tells Leonard that Amy just hurt his feelings and he wants to break up with her.
At Howard and Bernadette's, Howard says that he never thought he would say this, but he is missing Sheldon. Bernadette also says that she never thought she would say this, but Penny got the job. It was because she feels that Don really likes her. Stuart shows up saying he felt that Howard wasn't alright with him staying at Howard's mother's house. Howard tells him that he is living there rent-free and that he has no motivation to go out and get a job. Stuart notes that Howard is not his father. He then mentions "your mother and I" and Howard accuses him of not being his father. They start arguing and Howard accidentally calls Bernadette his mother. Stuart says that he wants him to apologize and leaves.
Walking up the stairs, Sheldon says that he wishes he never went on the trip. Amy tells him to consider it as an adventure which appeases Sheldon. He feels he was a caterpillar that has emerged as the world's smartest butterfly and is renewed and that he can face any new changes. Leonard quips that a butterfly could have gotten himself back from Arizona. Penny greets him and he sees that she cut her hair, causing him to leave again being unable to deal with the change.
Finally, Sheldon is showing Leonard and Penny the pictures he had taken on his trip, including those of a train bathroom he had visited and the Imodium he took so he wouldn't have to use the toilet. Then he talks about how he almost died in a fire in Des Moines, but he stayed put, and that’s when the Imodium gave out.
- Guest starring:
- Teleplay: Steven Molaro, Steve Holland & Eric Kaplan
- Story: Jim Reynolds, Maria Ferrari & Tara Hernandez
- Title Reference: The title refers to the interruption of Sheldon's soul-searching train trip.
- Taping date: August 12, 2014.
- Chuck Lorre's vanity card. 
- This episode was watched by 18.03 million people with a rating of 5.4 (adults 18-49).
- Total viewers including DVR users 23.75 million.
- The Big Bang Theory was ranked #4 for the week ending 28 September 2014.
- This episode aired in Canada on September, 2014 with 3.942 million viewers with a weekly ranking of #1.
- In Australia, it aired on October 13, 2014 with 1.348 million viewers.
- In Germany, it aired on January 5, 2015 with 2.16 million viewers.
- The start of the new season was threatened by the salary demands of the main three actors.
- Episode transcript 
- Jesse Schedeen for IGN - Anyone hoping for "The Locomotion Interruption" to maintain the more dramatic tone of "The Status Quo Combustion" was probably disappointed with the premiere. Sheldon's personal crisis seems to have resolved itself after 45 days of riding the rails, eating hot dogs, and downing bottles of Immodium. If anything, Sheldon seemed to completely forget why he left home in the first place...The rest of "The Locomotion Interruption" allowed viewers to catch up with the rest of the gang. By and large, these subplots were more successful. Penny showed signs of increased maturity...The Raj/Wolowitz material was also pretty entertaining as Wolowitz struggled with the idea that Stuart may have replaced him as the dutiful son. Or is Stuart the father figure here?...It's certainly a nice break from Stuart's typical brand of self-loathing, self-deprecating humor. 
- Dhruv Rao of The DR Club gave the episode a C+: "I generally give the writers the benefit of the doubt when it comes to season premieres because no matter how much you try you can never nail them. However, if you try your best, it will be the perfect stepping-stone to a new arc in a new season. Amy's desperation throughout the premiere didn't feel natural, nor did it feel comfortable. The same thing can be said about the comedy tonight: it felt like Chuck Lorre was trying a little too hard to get his jokes working, and I, like the controlled live studio audience tonight, didn't laugh at over baked jokes. Better luck next time..." 
- IMDb user reviews
- When Sheldon, Amy and Leonard are driving back from Kingman, Arizona, the background shows Utah State Highway 191 just north of Moab, Utah.
- Kevin Sussman is billed as "Starring" for the first time since season 6.
- The sixth episode to have a "Previously on The Big Bang Theory" review of past events. It summarizes "The Status Quo Combustion" (S7E24) and it is announced by Simon Helberg. The other five are "The Cohabitation Formulation" (S4E16), "The Skank Reflex Analysis" (S5E1), "The Countdown Reflection" (S5E24), "The Electric Can Opener Fluctuation" (S3E1) and "The Date Night Variable" (S6E1).
- This episodes takes place 45 days after the previous episode (S7E24).
- One of the stops on Sheldon's train trip was in Des Moines, Iowa. This is the hometown of his assistant, Alex Jensen.
- The officer that Sheldon talks to is named officer Hernandez. In the video game Grand Theft Auto: San Andreas made by Rockstar, one main police officer in the story is named Officer Hernandez. This could be a coincidence or it could be a reference.
- Kaley Cuoco, Jim Parsons and Johnny Galecki earn their first million dollar salary each.
- Sheldon also had his stuff stolen in "The Bozeman Reaction" (S3E13) and his pants stolen in the pilot (S1E1).
- This episode marks the first appearance of Penny with her new short pixie style haircut, which Kaley cut between filming of season 7 and 8.
- When Sheldon cries "shotgun" he probably wanted to ride in the front seat. Shotgun refers to the second person sitting next to the driver of a old western stagecoach who rode with a weapon to defend the stage coach. It might also to refer to armored cars or police vehicles in the 20th century. As a child-like character, he called "shot gun", but whispered it as to not yell out in a police station like someone had a firearm.
- Originally to be taped the week before; however, delayed due to contract negotiations.
- Bernadette is described as a bully though she was subjected to bullying when younger as discussed in "The Speckerman Recurrence" (S5E11).
- Kingman, AZ was listed as America's least educated city, which is ironic as smart as Sheldon feels he is that he got stranded there.
- When Leonard is talking to Sheldon on the phone, the Apartment 4A Flag on the fridge is upside down, presumably due to Sheldon being in distress from his train trip.
- As of this episode, Penny and Bernadette are co-workers once again ever since Bernadette's graduation from university in "The Roommate Transmogrification".
- Sheldon: Excuse me. Is it at all possible That you’re knitting a pair of pants?
- Howard: I just want to pop and make sure that Ma’s OK.
- Raj: I thought Stuart was looking after her.
- Howard: He was, but now that her cast is off, he moved out. Honestly, I’m kind of glad. It was getting a little weird.
- Raj: How so?
- Howard: I don’t know, they were getting a little chummy.
- Raj: Like us?
- Howard: No, not like us. Creepy chummy like you and your dog.
- (The scene of Leonard's car where Leonard and a not-so-happy Amy are travelling on the motorway)
- Leonard: Thanks again for coming. Six hours was gonna be a long drive by myself.
- Amy: (she's very jealous and sarcastic indeed) My pleasure. And I’m not angry at all that my boyfriend was in trouble and called you instead of me. I LOVE that!
- (Amy now thinks angrily for a little bit)
- Leonard: Yeah, time’s gonna fly by.
- (Leonard now twitches his lips for a second)
- (The scene at Howard and Bernadette’s apartment where Penny is complaining to Bernadette about her job interview)
- Penny: I haven’t been on a job interview in years. I’m really nervous.
- Bernadette: (she snaps at her crossly) Don’t be. You are built for pharmaceutical sales. You’re cute, you’re flirty and started that like there were gonna be three things.
- (Bernadette passes the sugar bowl to Penny)
- Penny: I don’t have any experience in sales. Unless you count the bikini car wash I did in high school. But you already made me take that off my résumé.
- Bernadette: (she speaks through her stroppy smile) This job is a lot like being a waitress, except instead of pushing the fish tacos ’cause they’re about to go bad, you’re just pushing our antidepressants before the FDA finds out they may cause rectal bleeding.
- Penny: They do?
- (Bernadette shrugs unhappily)
- Bernadette: (she speaks grumpily) Maybe. (Penny thinks for a second as she now gets very cross) But like our lawyers say, the world is full of things that can cause a rectum to bleed. Anyway, I talked you up to Dan. He’s the guy who’ll be interviewing you.
- Penny: Oh, I really appreciate this. I just hope I’m not in over my head.
- Bernadette: (she reassures her) You’ll be fine. Just be yourself.
- Penny: (she's really worried) I wish I felt more confident.
- Bernadette: (she informs her crossly) Penny. I wouldn't put you up for this job if I didn't think you could handle it.
- Penny: (she sighs) Oh thank you, but maybe I should cancel.
- Bernadette: (She is now very cross again) It’s too late to cancel. You’re going.
- Penny: But I don’t know anything about pharmaceuticals.
- Bernadette: (She is still very cross) Oh, I understand. You want something you’re really good at.
- (Penny continues looking sad whilst Bernadette says "I know" crossly to her out of shot. Now pan to the scene of Bernadette shouting at Penny with complete anger for the final time)
- Bernadette: (she yells loudly with big anger like Mrs. Wolowitz) Why don’t I get you a job at the “sitting around all day wearing yoga pants” factory?
- (Bernadette now picks up her coffee mug crossly and sips it in a huff. Penny thinks for a second and finally speaks to Bernadette)
- Penny: They’re comfortable.
- (Bernadette just continues to glare at Penny and get more crosser).
- Sheldon: Any word on my stolen items?
- Hernandez: We’re doing everything we can.
- Sheldon: You know, Sherlock Holmes liked to use cocaine to sharpen his focus. (Herendez glares crossly at Sheldon) But I’m sure those Cool Ranch Doritos are doing the trick.
- (Herendez frowns for a second. The office door opens and Leonard and Amy
- Leonard: Sheldon.
- Sheldon: (yelps with excitement and runs up to him) Oh. Leonard. Oh. I’m so happy to see you.
- Amy: Are you okay?
- Sheldon: Oh. I’m fine. Why did you come?
- Amy: What do you mean why did I come? You’re my boyfriend. I haven’t seen you in over a month. I just drove six hours to help you out. Don’t you have anything to say besides, “Why did you come?”
- Sheldon: I do, but…I feel uncomfortable saying it out loud in front of these police officers.
- Amy: Fine. Whisper it.
- Sheldon: Shotgun! (Sheldon leaves, with a frustrated Amy behind him)
- Don: So, why do you think you’d make a good pharmaceutical sales rep?
- Penny: Well, I’m a people person. People like me. Some of my favorite people are people. I feel like I’m saying “people” a lot. People. People. People. Pe.. OK, I’m done.
- Don: You sure?
- Penny: People. Yea.
- Howard: You wouldn't care if I slept with your mom?
- Raj: You know what? You’re my best friend and she’s in a bad marriage. I give you my blessing.
- Penny: Listen could you do me a favor and not tell Bernadette how badly I blow this interview? She’ll be upset and honestly I’m a little terrified of her.
- Don: Wait, wait. You’re scared of Bernadette?
- Penny: Yeah, kind of.
- Don: I thought it was just me! Everyone says she is so nice with that squeaky little voice.
- Penny: I know, but she kind of a bully.
- Don: She is. I didn't want to meet you, but I’m too scared to say no to her.
- (The scene of Leonard driving Sheldon and Amy in his car through the mountains of the Utah State Highway)
- Sheldon: At the hot dog stand in the Denver train station, Heinz ketchup. At the hot dog stand in the Salt Lake City train station, Heinz ketchup. At the hot dog stand in the Indianapolis train station?
- Leonard: (fed up by this) I don’t care.
- Sheldon: Wrong. Hunt’s. Hey, Amy, what do you say? You ready to move on to the mustard round?
- Amy: (she is now really, really cross) Have you not noticed that I’ve been sitting back here quietly stewing for the past two hours?
- Sheldon: I just thought you were bad at the game.
- (Amy shakes her head in fury)
- Amy: (so now a billion times angry) I’m mad at you. (Sheldon faces the furious Amy) How could you just go away like that without even saying good-bye, and then call Leonard for help instead of me?
- Sheldon: Amy, may I please have a moment of privacy to speak with my roommate?
- Amy: (she is still a billion times angry) We’re in a moving car. What do you expect me to do? Stick my fingers in my ears?
- Sheldon: Well, I was thinking put your head out the window like a dog, but that’ll work. Please? This’ll be quick. Leonard? As soon as we get home, I want to have coitus with Amy. Okay, she can’t hear. The reason I called you is because I didn’t want Amy to know I couldn’t make it on my own.
- Leonard: What’s the big deal?
- Sheldon: Oh, of course it’s no big deal to you. You idolize me, and nothing could ever knock me off that pedestal you put me on.
- Leonard: Well, yeah, it’s true. You, you are a god to me.
- Amy: Can I stop now?
- Leonard: Just tell her.
- Sheldon: I called Leonard because I failed. And I didn’t want you to think less of me.
- Amy: You were worried about that?
- Sheldon: Yes.
- Amy: Sheldon, it’s okay with me that you’re not perfect.
- Sheldon: Can I have one more moment with Leonard?
- Amy: Sure.
- Sheldon: Amy just hurt my feelings. I want to break up with her.
- (Scene: Howard and Bernadette’s apartment).
- Howard: Now, I never thought I’d say this, but I’m kind of excited to see Sheldon.
- Bernadette: I never thought I’d say this, but Penny got a job today.
- Howard: She did?
- Bernadette: Well, the only reason she got it is ’cause the guy who interviewed her loves me.
- Howard (answering a knock on the door): What do you want?
- Stuart: I, uh, kind of got the feeling you might not be okay with me staying at your mom’s.
- Howard: You’re right, I’m not. I think it’s weird.
- Bernadette: (she is now very cross) Howie?
- Howard: It is. He’s a grown man. He’s just gonna live there rent-free? How is that gonna motivate him to get off his butt and get a job? I mean, do you even have a plan?
- Stuart: Hey, you’re not my father, okay? And besides, your mother and I were talking…
- Howard: Your mother and I? You’re not my father.
- Stuart: I didn’t say I was your father.
- Howard: Well, I didn’t say I was your father.
- Bernadette: (she is still very cross) Okay, calm down. You’re not his father, he’s not your father. Nobody’s anybody’s father.
- Stuart: I, I’m sorry you don’t like my life choices, but it’s my life.
- Howard: Well, it’s my house, it’s my rules.
- Stuart: Oh, oh, okay, Dad, if I mow the lawn, can I have my allowance?
- Bernadette: (she now is hugely cross by all of this) Hey, don’t you take that sarcastic tone with him.
- Stuart: I don’t have to listen to you.
- Howard: Don’t talk to her like that. That is my mother. Wife. My wife. I said my wife.
- (Bernadette has almost had enough of Howard and Stuart's argument)
- Stuart: You know what? This isn’t getting us anywhere. When you’re ready to apologize, you know where to find me.
- Howard: Yeah, in my house.
- Stuart: (out of vision) That’s right, sucka.
- Amy: See. The trip was good for you.
- Sheldon: Indeed. I was the world’s smartest caterpillar. And after pupating on our nation’s railway system I burst forth as the world’s smartest butterfly.
- Leonard: Butterfly could have gotten himself home from Arizona.
- Sheldon: Now I feel renewed. I’m ready to deal with any changes that come my way.
- Penny: Hey. Look who’s back.
- Sheldon: Your hair is different. You changed your hair. I can’t take this. I’m out.
-  Taping Report by The ShamyShipper and Tomasina