When Sheldon makes friend with an older girl who introduces him to a new field of science, Mary and George are conflicted on how to handle Sheldon's maturing social life.
Quote from Adult Sheldon
Adult Sheldon: As you can see, sometimes a person can be both incredibly intelligent and full of baloney.
Quote from Adult Sheldon
Adult Sheldon: Anger is an ugly emotion. Unbridled rage even more so. And when it bubbled up inside me, I channeled it the only way I knew how. I cleaned the house like a man possessed.
Quote from Tam
Mary: You smoke marijuana?
Sheldon: Mom!
Libby: No, ma'am.
Tam: Just say no. [Mary shoots him an unimpressed look]
Quote from George Jr.
George Sr.: Oh.
George Jr.: Oh, what?
George Sr.: You didn't mention she was black.
George Jr.: Was I supposed to?
George Sr.: No, 'course not.
George Jr.: Then why bring it up?
George Sr.: It just wasn't what I was expecting.
George Jr.: What were you expecting?
George Sr.: It's a big school. Why are you right here?
George Jr.: They've got some books in there about Martin Luther King. Maybe you should go read one.
Quote from Mary
Sheldon: Regardless, I'm not interested in making any more friends.
Mary: Oh, I don't think that's how you really feel.
Sheldon: It is. From now on, it's a hermit's life for me.
Mary: I bet, when you grow up, you will be surrounded by lots of smart, wonderful friends.
Sheldon: I can't see that happening.
I Wanna Rock
Twisted Sister
Libby showing Sheldon and Tam the delights of geology.
We're Not Gonna Take It
Twisted Sister
As Sheldon cleans the house in a rage.
As Sheldon and Tam eat their lunch in the school library, Sheldon mentions that he heard you could punch a hole in a floppy disk and make it double-sided, but he feels it is dishonest when you didn’t pay for double-sided storage. When Sheldon sees a girl take a book on geostatistics, Sheldon wonders who the mystery woman is. Tam wants to invite her to have lunch with them and, to appeal to the scientist in Sheldon, suggests thinking of it as an experiment. Tam proposes that Sheldon goes over to ask her as his lack of testosterone makes him adorable to women. When Sheldon goes and introduces himself to the girl, she already knows who he is; after all, he is the only nine-year-old in the school. Sheldon invites her to have lunch with them so they can have a spirited discussion about geostatistics. She is surprised and charmed by the fact he really is as smart as everybody says.
A little while later, Libby has joined Sheldon and Tam’s social group. As they eat lunch together in the library, Sheldon is talking about her plans to be a geologist when she grows up. After lunch, as the trio walk the hallways, Tam tells her they eat in the library every day and she is welcome to join them. Georgie is standing by his locker when he sees Sheldon saying bye to Libby.
At that dinner that night, Mary asks the kids how their day at school went. When Georgie says that Sheldon’s got a girlfriend, Sheldon disputes that characterization. After Meemaw wonders if it’s time to have “the talk” with Sheldon, he says he already knows how the human reproductive system works as Missy told him.
When the expanded social group meets in the library for lunch. Sheldon is debating Libby’s assertion that without geology there would be no theory of evolution. When an infatuated Tam compliments Libby on her mind and her eyes, Sheldon wants him to stop as they’re eating. Meanwhile, George is watching the kids through the library window when Georgie walks by and accuses him of spying. George is surprised to see Sheldon’s friend is black and wonders why his son didn’t mention that, but Georgie didn’t think it was a meaningful detail.
Back inside the library, Sheldon asks Libby why it took so long for people to believe in continental drift when it’s obvious that Africa and South America fit together. Tam doesn’t believe that, until he walks over to a globe. Sheldon admits he’s both threatened and delighted by Libby’s brain.
At home, Sheldon is joking on the phone with Libby as a concerned Mary walks by. When she goes into the kitchen where George and Meemaw are doing the dishes, Mary wonders what’s happening with Sheldon. George can’t believe it; Sheldon has been on the phone for over an hour. When Georgie wonders why Sheldon gets to tie up the phone but he can’t, Meemaw argues it’s a miracle what’s happening with Sheldon, and God-fearing people don’t get in the way of those. Mary is concerned as she hears Sheldon chatting breezily on the phone.
Libby impresses Sheldon and Tam by showing off some rock specimens under a blue light in the school’s science lab. Later, the trio search for tektites in a nearby ravine, although Sheldon opts against touching tektites on account of their similarity to raccoon feces. Back in the lab, Libby shows them the “clean cleavage” of a gypsum sample at school, while Sheldon is unimpressed by Tam’s immature cleavage joke. Finally, Sheldon is wowed as Libby shows them the inside of a geode.
In the backyard, Mary goes to see George as he works on his motorcycle. Mary is concerned about how much time Sheldon is spending with Libby, arguing he’s a little too young to be hanging out with teenagers. George doesn’t see the problem as Sheldon’s only young on the outside; inside he’s like an old man. Thinking she isn’t getting anywhere, Mary turns around and says she’s sorry she bothered. As she walks away, George stops her and asks what she thought would happen when they sent him to high school. Mary thought he’d learn stuff but still be her baby. George thinks this is good for Sheldon and will prepare him for college, which may only be a few years away.
As a nervous Sheldon stands outside the boys’ bathroom at school, Libby sees him and wonders what he’s doing. Sheldon says he needs to use the bathroom but knows it can get uncivilized in there. Libby checks if there’s anyone in there and, when it’s clear, she tells Sheldon to go in while she stands guard. While Sheldon does his business, Libby stops one boy who from entering the bathroom. When he emerges from the bathroom, Sheldon thanks Libby and wonders where she’s been his whole life. Adult Sheldon remarks that the person who said the fastest way to a man’s heart was through his stomach did not consider his tiny bladder.
As the group eat lunch again, they are debating the best Space Shuttle names. When Libby remarks that they’re playing a space shuttle movie at the Museum of Natural Science in IMAX, Sheldon wonders how they’ll get there as it’s in Houston. After Libby says she’ll drive, Tam instantly agrees to attend. Sheldon is surprised that Tam didn’t even think of getting his parents’ approval first.
When Mary sits down at the kitchen table with George and Meemaw, she is upset by Sheldon’s request to see a movie in Houston with Libby. George is also concerned, but only at the prospect of having to drive to Houston. When Mary says Libby will be driving them, George thinks it’s great. Mary says it’s not great and she doesn't want her little boy in some car with a teenager behind the wheel.
As Sheldon plays with his train set in the garage, Mary comes to talk to him. When Sheldon gets his train back to the station so as not to disappoint his commuters, Mary tells him that she has given it a lot of thought and doesn’t think he can go to Houston with Libby. Mary offers to drive him there so he can meet up with his friends, but Sheldon doesn’t want to go with his mommy.
As the unbridled rage courses through Sheldon’s veins, he channels it the only way he knows how: he anger cleans the whole house. He scrubs pans in the kitchen, dusts the mantelpiece, vacuums the living room, scrubs the shower, and even cleans the outside of Georgie’s bedroom window. As he angrily throws laundry into the dryer, Mary wonders what she’s supposed to do. Meemaw suggests sending Sheldon over to her house before he runs out of gas. When Mary goes over to talk to Sheldon, she makes him a deal: she’ll let him go to Houston so long as she can meet Libby first.
When the doorbell rings, Mary welcomes Libby and Tam and asks them to take a seat. Mary tells Libby she hopes she’ll forgive her, but she wanted to meet the person driving her nine-year-old son to Houston. Libby is understanding as Mary asks her about her driving history and whether she’s made this trip before. When Mary goes on to ask if she smokes marijuana, Libby answers no. Mary says she finds this very reassuring and, having met Libby, is feeling a lot better. Libby tells Mary that she has nothing to worry about as she’s been babysitting kids for years. Those words instantly cut through Sheldon and he quickly excuses himself, saying he’s not feeling well and they’ll have to go without him.
As Sheldon cries on his bed, Mary comes to see what’s wrong. Sheldon says he doesn’t want to talk about it, but he also doesn’t want to be left alone. Sheldon says he thought he and Libby were equals, yet just she thinks of him as a child. When Mary points out she is almost twice his age, Sheldon says there’s people five times his age who are stupider than he is. Mary argues this isn’t just about being smart, that there are other kinds of maturity. When Missy comes in and wonders why her brother is crying, Mary insists it’s none of her business and asks her to leave. Returning to Sheldon, Mary continues to tell him about the different kinds of maturity that have nothing to do with being smart. After realizing that Mary was hinting that he isn’t emotionally mature, Sheldon goes on to say he’s now done with making friends. Mary doesn’t think that’s how he really feels. She bets that when grows up he will be surrounded by lots of smart, wonderful friends.
In the school library, Tam sits down with Sheldon. When Sheldon asks Tam how the IMAX movie was, Tam says it got a little uncomfortable; Tam tried to put his arm around Libby and she quickly shot him down. After Sheldon says he’s been giving geology some thought and no longer consider it a real science, Tam says he could go along with that.