The Line Substitution Solution

"The Line Substitution Solution" is the twenty-third and penultimate episode of the ninth season of the American sitcom The Big Bang Theory. The episode aired on Thursday, May 5, 2016.

Summary
Sheldon hires Stuart to spend the with Amy when he’d rather go to a  screening. Also, Leonard’s mother, Beverly, comes to Pasadena and Penny struggles to make a connection with her even planning a redo of their wedding.

Extended Plot
Penny and Sheldon are on the couch with trying to expand their respective  bases. Penny has s and Sheldon has. Leonard comes in and is able to both of their cards. Leonard asks Penny to go with him to the to pick up his mother. Penny agrees to join him. Leonard then asks her since she will already be at the airport, could she pick her up? It would give her a chance to with her and Leonard wouldn't be subjected to her. Penny agrees and that she should have a good relationship with her.

At the comic book store the guys are discussing the screening of that includes  on a first-come first-served basis. will be having a. They guys plan on getting in line early. Beverly is busy with Penny; however, Sheldon has to go with Amy. The boys offer to hold him a space in line; however, Sheldon feels that that violates line. Howard mentions that he could someone to stand in line for him. Stuart thinks that is until he finds they can make $20 an.

Leaving the, Beverly is not surprised that Leonard avoided her and is asking Penny about their before they leave the. Penny changes the subject to each other about the latest  they had read, but her last one was a. "Don't everything I say." Penny then proposes together, but adds her friends to make the  sound less.

Stuart gets into the with Amy. Amy remarks that he is not Sheldon. Stuart figured that that might come up. Sheldon has him to go shopping with her. Amy says that they are not going to do that and she is very annoyed. Stuart snaps that he just works here.

At the movies, the guys about previous lines they had waited in. Stuart shows up and calls Sheldon the most inconsiderate he has met in his entire. Amy hired him to at Sheldon. Sheldon tells him that turnabout is fair play; while Stuart then really shouts at him calling Sheldon a jerk.

Amy is about the progress she thought she was making with Sheldon. Beverly knows how brilliant Sheldon is and that being in a relationship could be trying. She Amy's resolve and tells her that she is an extraordinary. Penny wants to bond with Beverly like Amy is. Stuart arrives with and an  that Sheldon paid for. Amy offers Bernadette five dollars to slam the in his.

Stuart returns to the and tells Sheldon that his apology was not accepted. Leonard suggests that Sheldon apologize in. Stuart offers to hold Sheldon's place in line for a and Sheldon leaves.

Bernadette tries to talk Penny up mentioning her status as the number three at their pharmaceutical company. She mentions that she is a and her work with some new  s that all three  find interesting and discuss in front of Penny. On Bernadette's urging Penny had mentioned something great about her new company car. It has seat warmers. Sheldon then shows up at the apartment gives Amy a specific three part apology. Amy replies, "Fine." Sheldon has to leave because he has an downstairs and the movie line could start moving any.

Leonard and Howard are making fun of Raj and the cane seat he was using. Sheldon rushes back out of explaining that his apology went fine. A young man runs up and joins his s in front of Sheldon. Leonard tells Sheldon to let it be. Sheldon confronts the interloper, who says that his friends saved him a place. After Sheldon rants about line etiquette, the guy wants to know who made him line monitor. Mrs. Wunch in the fourth grade. Next he wants to know if Sheldon is for real. Leonard replies that unfortunately, yes.

Beverly is impressed with their relationship and wants to them for a new book she is writing about high achieving. Amy mentions that Bernadette is married to an ex-. Would they like to be interviewed? Sure. In the, Howard pretends to interview himself. Bernadette wonders if she would like to interview Penny. "About what?" replies Beverly. Now Penny is since she has been trying to connect with Beverly all day. Beverly wonders if she is trying to connect or have some form of. Penny then says that she has been her all day. Does she even know what an insult is? Like when Penny her son without even telling her? Penny is stumped and tells her that that is a good.

Now Sheldon is arguing about line-cutting and the {{w|rules that {{w|the Avengers live by. Then he ask the rest of the line behind him whether they take issue with this guy line-cutting. No one does. Someone at the back of the line is not getting in because of him. Then he brings up the {{w|story of {{w|Rosa Parks who stood up for a cause, though she actually remained seated on the {{w|bus. An {{w|African-America woman reminds Sheldon that he had paid Stuart to hold his place in line, so he cut. But to Sheldon his circumstance was "{{w|swapsies" and not "cutsies". The line starts to move and Leonard tells him to let it go since he did everything he could do including denigrating the memory of a great {{w|civil rights leader.

Penny tells Beverly that she is surprised that she even cared about the {{w|wedding. Beverly said that she was {{w|human and wanted to get an {{w|invitation. Amy tells her that none of them knew. Bernadette mentions that {{w|live-streaming of the wedding. Penny asked Beverly if she would have come. Beverly replied in the {{w|negative, but would have told her that she was making a big {{w|mistake. Penny is crushed. On the other hand Beverly has never seen Leonard so {{w|happy so perhaps she was {{w|wrong. "Wow", replied Penny who then proposed that they get married again in front of her and their friends while Beverly was in {{w|town. Beverly finds that perfectly acceptable. Penny exclaims joyfully that she would find that "perfectly acceptable" and that they have bonded. She gives Beverly a big {{w|hug as Beverly doesn't change her expression and gently pats her.

Finally, Bernadette is getting ready for {{w|bed and asks him if he was okay since he'd been in the {{w|bathroom a while. He's fine. As Bernadette leaves the {{w|bedroom, she {{w|smiles listening to Howard interview himself.

Credits

 * Guest starring:
 * Christine Baranski as Beverly Hofstadter
 * Blake Anderson as Trevor
 * Amanda Payton as Ainsley
 * Teleplay: Steven Molaro, Eric Kaplan & Maria Ferrari
 * Story: Steve Holland, Saladin K. Patterson & Tara Hernandez

Critics
To be entered.

Trivia

 * Second season that Beverly appeared twice in the same season. The first season was Season 7. She previously appeared in the episode "The Celebration Experimentation."
 * It's very likely that the guys are waiting in line to watch "".
 * First time that Beverly is seen inside Apartment 4B.
 * Beverly actually acknowledges that she has never seen Leonard happier since marrying Penny, so maybe it wasn't such a bad thing. She was insulted that she didn't get an invitation though she wouldn't have attended. She would have watched the broadcast on-line.
 * In the 200th episode, The Celebration Experimentation, when Penny says that they got married and didn't invite her, Beverly answers "And I never did thank you for that dear" but in this episode she says she's insulted by it.
 * Penny's suggestion sets up the plot of the [Season 9] finale.

Quotes

 * Stuart: (crossly) Sheldon, you are the most inconsiderate person I have ever met in my entire life. Where do you get off sending ME to shop with YOUR girlfriend?
 * Sheldon: (nervous) I don't understand. You were happy to do this when I hired you. Wh-why are you upset with me now?
 * Stuart: (calm) Oh, I'm not upset with you. But Amy is pretty bent out of shape, so she hired me to let you have it.
 * Sheldon: Well, I suppose turnabout is fair play
 * Stuart: (furious for Amy) YOU'RE DARN RIGHT IT'S FAIR PLAY, YOU SELFISH JERK!


 * Stuart: (holding a bouquet of flowers) Sheldon says he's sorry.
 * Amy: (crossly) Bernadette, I'll give you $5 to slam the door.
 * Stuart: (as the door closes) I would've done it for $3.